Sensors

34 pages, 1585 KB

Open AccessArticle

LoWMob: Intra-PAN Mobility Support Schemes for 6LoWPAN

by Gargi Bag^1,*, Muhammad Taqi Raza², Ki-Hyung Kim¹ and Seung-Wha Yoo¹

¹ Information and Communication Department/Ajou University, South Korea

² USN Networking Research Team / Electronics and Telecommunications Research Institute (ETRI), Korea

Sensors 2009, 9(7), 5844-5877; https://doi.org/10.3390/s90705844 - 23 Jul 2009

Cited by 65 | Viewed by 14768

Abstract

Mobility in 6LoWPAN (IPv6 over Low Power Personal Area Networks) is being utilized in realizing many applications where sensor nodes, while moving, sense and transmit the gathered data to a monitoring server. By employing IEEE802.15.4 as a baseline for the link layer technology, [...] Read more.

Mobility in 6LoWPAN (IPv6 over Low Power Personal Area Networks) is being utilized in realizing many applications where sensor nodes, while moving, sense and transmit the gathered data to a monitoring server. By employing IEEE802.15.4 as a baseline for the link layer technology, 6LoWPAN implies low data rate and low power consumption with periodic sleep and wakeups for sensor nodes, without requiring them to incorporate complex hardware. Also enabling sensor nodes with IPv6 ensures that the sensor data can be accessed anytime and anywhere from the world. Several existing mobility-related schemes like HMIPv6, MIPv6, HAWAII, and Cellular IP require active participation of mobile nodes in the mobility signaling, thus leading to the mobility-related changes in the protocol stack of mobile nodes. In this paper, we present LoWMob, which is a network-based mobility scheme for mobile 6LoWPAN nodes in which the mobility of 6LoWPAN nodes is handled at the network-side. LoWMob ensures multi-hop communication between gateways and mobile nodes with the help of the static nodes within a 6LoWPAN. In order to reduce the signaling overhead of static nodes for supporting mobile nodes, LoWMob proposes a mobility support packet format at the adaptation layer of 6LoWPAN. Also we present a distributed version of LoWMob, named as DLoWMob (or Distributed LoWMob), which employs Mobility Support Points (MSPs) to distribute the traffic concentration at the gateways and to optimize the multi-hop routing path between source and destination nodes in a 6LoWPAN. Moreover, we have also discussed the security considerations for our proposed mobility schemes. The performance of our proposed schemes is evaluated in terms of mobility signaling costs, end-to-end delay, and packet success ratio. Full article

(This article belongs to the Special Issue Wireless Sensor Technologies and Applications)

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19 pages, 596 KB

Open AccessArticle

Fundamentals of in Situ Digital Camera Methodology for Water Quality Monitoring of Coast and Ocean

by Lonneke Goddijn-Murphy^1,2,*, Damien Dailloux^3,4, Martin White¹ and Dave Bowers⁵

¹ Department of Earth and Ocean Sciences, National University of Ireland, Galway, Ireland

² Current address: Environmental Research Institute, North Highland College, UHI Millennium Institute, Thurso, Caithness, Scotland, KW14 7JD, UK

³ Laboratoire des Sciences, Appliques au Génie Civile et Côtier, Université de Pau et des Pays de l’Adour, 1 allée du parc Montary, 64600 Anglet, France

⁴ AZTI-Tecnalia, Herrera Kaia, Portu aldea z/g, 20110 Pasai (Gipuzcoa), Spain

⁵ School of Ocean Sciences, University of Wales, Menai Bridge, Gwynedd LL59 5EY, UK

Sensors 2009, 9(7), 5825-5843; https://doi.org/10.3390/s90705825 - 22 Jul 2009

Cited by 38 | Viewed by 15314

Abstract

Conventional digital cameras, the Nikon Coolpix885^® and the SeaLife ECOshot^®, were used as in situ optical instruments for water quality monitoring. Measured response spectra showed that these digital cameras are basically three-band radiometers. The response values in the red, green [...] Read more.

Conventional digital cameras, the Nikon Coolpix885^® and the SeaLife ECOshot^®, were used as in situ optical instruments for water quality monitoring. Measured response spectra showed that these digital cameras are basically three-band radiometers. The response values in the red, green and blue bands, quantified by RGB values of digital images of the water surface, were comparable to measurements of irradiance levels at red, green and cyan/blue wavelengths of water leaving light. Different systems were deployed to capture upwelling light from below the surface, while eliminating direct surface reflection. Relationships between RGB ratios of water surface images, and water quality parameters were found to be consistent with previous measurements using more traditional narrow-band radiometers. This current paper focuses on the method that was used to acquire digital images, derive RGB values and relate measurements to water quality parameters. Field measurements were obtained in Galway Bay, Ireland, and in the Southern Rockall Trough in the North Atlantic, where both yellow substance and chlorophyll concentrations were successfully assessed using the digital camera method. Full article

(This article belongs to the Special Issue Image Sensors 2009)

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Graphical abstract

15 pages, 128 KB

Open AccessArticle

Evanescent Wave Fiber Optic Biosensor for Salmonella Detection in Food

by Angela M. Valadez¹, Carlos A. Lana², Shu-I Tu³, Mark T. Morgan¹ and Arun K. Bhunia^1,*

¹ Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, Indiana 47907, USA

² School of Aeronautics & Astronautics, Purdue University, 701 W. Stadium Ave., West Lafayette, Indiana 47907, USA

³ United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA

Sensors 2009, 9(7), 5810-5824; https://doi.org/10.3390/s90705810 - 21 Jul 2009

Cited by 82 | Viewed by 16030

Abstract

Salmonella enterica is a major food-borne pathogen of world-wide concern. Sensitive and rapid detection methods to assess product safety before retail distribution are highly desirable. Since Salmonella is most commonly associated with poultry products, an evanescent wave fiber-optic assay was developed to detect [...] Read more.

Salmonella enterica is a major food-borne pathogen of world-wide concern. Sensitive and rapid detection methods to assess product safety before retail distribution are highly desirable. Since Salmonella is most commonly associated with poultry products, an evanescent wave fiber-optic assay was developed to detect Salmonella in shell egg and chicken breast and data were compared with a time-resolved fluorescence (TRF) assay. Anti-Salmonella polyclonal antibody was immobilized onto the surface of an optical fiber using biotin-avidin interactions to capture Salmonella. Alexa Fluor 647-conjugated antibody (MAb 2F-11) was used as the reporter. Detection occurred when an evanescent wave from a laser (635 nm) excited the Alexa Fluor and the fluorescence was measured by a laser-spectrofluorometer at 710 nm. The biosensor was specific for Salmonella and the limit of detection was established to be 10³ cfu/mL in pure culture and 10⁴ cfu/mL with egg and chicken breast samples when spiked with 10²cfu/mL after 2–6 h of enrichment. The results indicate that the performance of the fiber-optic sensor is comparable to TRF, and can be completed in less than 8 h, providing an alternative to the current detection methods. Full article

(This article belongs to the Section Biosensors)

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27 pages, 718 KB

Open AccessReview

Waveguide-Based Biosensors for Pathogen Detection

by Harshini Mukundan¹, Aaron S. Anderson¹, W. Kevin Grace¹, Karen M. Grace², Nile Hartman³, Jennifer S. Martinez⁴ and Basil I. Swanson^1,*

¹ Physical Chemistry and Applied spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

² Integrated Space Research-4, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

³ nGimat™, 5315, Peachtree Industrial Blvd., Atlanta, GA30341, USA

⁴ Centers for Integrated Nanotechnology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

Sensors 2009, 9(7), 5783-5809; https://doi.org/10.3390/s90705783 - 21 Jul 2009

Cited by 181 | Viewed by 24966

Abstract

Optical phenomena such as fluorescence, phosphorescence, polarization, interference and non-linearity have been extensively used for biosensing applications. Optical waveguides (both planar and fiber-optic) are comprised of a material with high permittivity/high refractive index surrounded on all sides by materials with lower refractive indices, [...] Read more.

Optical phenomena such as fluorescence, phosphorescence, polarization, interference and non-linearity have been extensively used for biosensing applications. Optical waveguides (both planar and fiber-optic) are comprised of a material with high permittivity/high refractive index surrounded on all sides by materials with lower refractive indices, such as a substrate and the media to be sensed. This arrangement allows coupled light to propagate through the high refractive index waveguide by total internal reflection and generates an electromagnetic wave—the evanescent field—whose amplitude decreases exponentially as the distance from the surface increases. Excitation of fluorophores within the evanescent wave allows for sensitive detection while minimizing background fluorescence from complex, “dirty” biological samples. In this review, we will describe the basic principles, advantages and disadvantages of planar optical waveguide-based biodetection technologies. This discussion will include already commercialized technologies (e.g., Corning’s EPIC^® Ô, SRU Biosystems’ BIND^™, Zeptosense^®, etc.) and new technologies that are under research and development. We will also review differing assay approaches for the detection of various biomolecules, as well as the thin-film coatings that are often required for waveguide functionalization and effective detection. Finally, we will discuss reverse-symmetry waveguides, resonant waveguide grating sensors and metal-clad leaky waveguides as alternative signal transducers in optical biosensing. Full article

(This article belongs to the Special Issue Pathogen Sensors)

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13 pages, 752 KB

Open AccessArticle

Potential of ILRIS3D Intensity Data for Planar Surfaces Segmentation

by Chi-Kuei Wang^* and Yao-Yu Lu

Department of Geomatics, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan

Sensors 2009, 9(7), 5770-5782; https://doi.org/10.3390/s90705770 - 20 Jul 2009

Cited by 6 | Viewed by 12079

Abstract

Intensity value based point cloud segmentation has received less attention because the intensity value of the terrestrial laser scanner is usually altered by receiving optics/hardware or the internal propriety software, which is unavailable to the end user. We offer a solution by assuming [...] Read more.

Intensity value based point cloud segmentation has received less attention because the intensity value of the terrestrial laser scanner is usually altered by receiving optics/hardware or the internal propriety software, which is unavailable to the end user. We offer a solution by assuming the terrestrial laser scanners are stable and the behavior of the intensity value can be characterized. Then, it is possible to use the intensity value for segmentation by observing its behavior, i.e., intensity value variation, pattern and presence of location of intensity values, etc. In this study, experiment results for characterizing the intensity data of planar surfaces collected by ILRIS3D, a terrestrial laser scanner, are reported. Two intensity formats, grey and raw, are employed by ILRIS3D. It is found from the experiment results that the grey intensity has less variation; hence it is preferable for point cloud segmentation. A warm-up time of approximate 1.5 hours is suggested for more stable intensity data. A segmentation method based on the visual cues of the intensity images sequence, which contains consecutive intensity images, is proposed in order to segment the 3D laser points of ILRIS3D. This method is unique to ILRIS3D data and does not require radiometric calibration. Full article

(This article belongs to the Special Issue LiDAR for 3D City Modeling)

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Graphical abstract

30 pages, 519 KB

Open AccessReview

Surface Generated Acoustic Wave Biosensors for the Detection of Pathogens: A Review

by María-Isabel Rocha-Gaso¹, Carmen March-Iborra², Ángel Montoya-Baides² and Antonio Arnau-Vives^1,*

¹ Grupo de Fenómenos Ondulatorios, Departamento de Ingeniería Electrónica, Universidad Politécnica de Valencia, Spain

² Instituto Interuniversitario de Investigación en Bioingeniería y Tecnología Orientada al Ser Humano, Universidad Politécnica de Valencia, Spain

Sensors 2009, 9(7), 5740-5769; https://doi.org/10.3390/s90705740 - 20 Jul 2009

Cited by 227 | Viewed by 28492

Abstract

This review presents a deep insight into the Surface Generated Acoustic Wave (SGAW) technology for biosensing applications, based on more than 40 years of technological and scientific developments. In the last 20 years, SGAWs have been attracting the attention of the biochemical scientific [...] Read more.

This review presents a deep insight into the Surface Generated Acoustic Wave (SGAW) technology for biosensing applications, based on more than 40 years of technological and scientific developments. In the last 20 years, SGAWs have been attracting the attention of the biochemical scientific community, due to the fact that some of these devices - Shear Horizontal Surface Acoustic Wave (SH-SAW), Surface Transverse Wave (STW), Love Wave (LW), Flexural Plate Wave (FPW), Shear Horizontal Acoustic Plate Mode (SH-APM) and Layered Guided Acoustic Plate Mode (LG-APM) - have demonstrated a high sensitivity in the detection of biorelevant molecules in liquid media. In addition, complementary efforts to improve the sensing films have been done during these years. All these developments have been made with the aim of achieving, in a future, a highly sensitive, low cost, small size, multi-channel, portable, reliable and commercially established SGAW biosensor. A setup with these features could significantly contribute to future developments in the health, food and environmental industries. The second purpose of this work is to describe the state-of-the-art of SGAW biosensors for the detection of pathogens, being this topic an issue of extremely importance for the human health. Finally, the review discuses the commercial availability, trends and future challenges of the SGAW biosensors for such applications. Full article

(This article belongs to the Special Issue Pathogen Sensors)

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25 pages, 838 KB

Open AccessArticle

Adaptive Momentum-Based Motion Detection Approach and Its Application on Handoff in Wireless Networks

by Tein-Yaw Chung^*, Yung-Mu Chen and Chih-Hung Hsu

Department of Computer Science & Engineering, Yuan Ze University, No. 135 Yuan-Tung Rd., Chung-Li, Taoyuan, 32003, Taiwan

Sensors 2009, 9(7), 5715-5739; https://doi.org/10.3390/s90705715 - 17 Jul 2009

Cited by 10 | Viewed by 11964

Abstract

Positioning and tracking technologies can detect the location and the movement of mobile nodes (MNs), such as cellular phone, vehicular and mobile sensor, to predict potential handoffs. However, most motion detection mechanisms require additional hardware (e.g., GPS and directed antenna), costs (e.g., power [...] Read more.

Positioning and tracking technologies can detect the location and the movement of mobile nodes (MNs), such as cellular phone, vehicular and mobile sensor, to predict potential handoffs. However, most motion detection mechanisms require additional hardware (e.g., GPS and directed antenna), costs (e.g., power consumption and monetary cost) and supply systems (e.g., network fingerprint server). This paper proposes a Momentum of Received Signal Strength (MRSS) based motion detection method and its application on handoff. MRSS uses the exponentially weighted moving average filter with multiple moving average window size to analyze the received radio signal. With MRSS, an MN can predict its motion state and make a handoff trigger at the right time without any assistance from positioning systems. Moreover, a novel motion state dependent MRSS scheme called Dynamic MRSS (DMRSS) algorithm is proposed to adjust the motion detection sensitivity. In our simulation, the MRSSand DMRSS-based handoff algorithms can reduce the number of unnecessary handoffs up to 44% and save battery power up to 75%. Full article

(This article belongs to the Special Issue Motion Detectors)

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13 pages, 567 KB

Open AccessArticle

Antioxidant Activity and Total Phenolic and Flavonoid Contents of Hieracium pilosella L. Extracts

by Ljiljana Stanojević^1,*, Mihajlo Stanković¹, Vesna Nikolić¹, Ljubiša Nikolić¹, Dušica Ristić¹, Jasna Čanadanovic-Brunet² and Vesna Tumbas²

¹ University of Nis, Faculty of Technology, Bulevar Oslobodjenja 124, 16000 Leskovac, Serbia

² University of Novi Sad, Faculty of Technology, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia

Sensors 2009, 9(7), 5702-5714; https://doi.org/10.3390/s90705702 - 16 Jul 2009

Cited by 142 | Viewed by 21433

Abstract

The antioxidant activity ofwater, ethanol and methanol Hieracium pilosella L.extracts is reported. The antioxidative activity was tested by spectrophotometrically measuring their ability to scavenge a stable DPPH^· free radical and a reactive hydroxyl radical trapped by DMPO during the Fenton reaction, using [...] Read more.

The antioxidant activity ofwater, ethanol and methanol Hieracium pilosella L.extracts is reported. The antioxidative activity was tested by spectrophotometrically measuring their ability to scavenge a stable DPPH^· free radical and a reactive hydroxyl radical trapped by DMPO during the Fenton reaction, using the ESR spectroscopy. Total phenolic content and total flavonoid content were evaluated according to the Folin-Ciocalteu procedure, and a colorimetric method, respectively. A HPLC method was used for identification of some phenolic compounds (chlorogenic acid, apigenin-7-O-glucoside and umbelliferone). The antioxidant activity of the investigated extracts slightly differs depending on the solvent used. The concentration of 0.30 mg/mL of water, ethanol and methanol extract is less effective in scavenging hydroxyl radicals (56.35, 58.73 and 54.35%, respectively) in comparison with the DPPH^· radical scavenging activity (around 95% for all extracts). The high contents of total phenolic compounds (239.59–244.16 mg GAE/g of dry extract) and total flavonoids (79.13–82.18 mg RE/g of dry extract) indicated that these compounds contribute to the antioxidative activity. Full article

(This article belongs to the Section Biosensors)

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23 pages, 2652 KB

Open AccessArticle

Object-Based Integration of Photogrammetric and LiDAR Data for Automated Generation of Complex Polyhedral Building Models

by Changjae Kim and Ayman Habib^*

Department of Geomatics Engineering, The University of Calgary, 2500 University Drive NW, T2N 1N4, Calgary, Canada

Sensors 2009, 9(7), 5679-5701; https://doi.org/10.3390/s90705679 - 15 Jul 2009

Cited by 44 | Viewed by 9472

Abstract

This research is concerned with a methodology for automated generation of polyhedral building models for complex structures, whose rooftops are bounded by straight lines. The process starts by utilizing LiDAR data for building hypothesis generation and derivation of individual planar patches constituting building [...] Read more.

This research is concerned with a methodology for automated generation of polyhedral building models for complex structures, whose rooftops are bounded by straight lines. The process starts by utilizing LiDAR data for building hypothesis generation and derivation of individual planar patches constituting building rooftops. Initial boundaries of these patches are then refined through the integration of LiDAR and photogrammetric data and hierarchical processing of the planar patches. Building models for complex structures are finally produced using the refined boundaries. The performance of the developed methodology is evaluated through qualitative and quantitative analysis of the generated building models from real data. Full article

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Graphical abstract

15 pages, 274 KB

Open AccessArticle

A Survey of Geosensor Networks: Advances in Dynamic Environmental Monitoring

by Silvia Nittel

Spatial Information Science & Engineering, University of Maine / Orono, ME, USA

Sensors 2009, 9(7), 5664-5678; https://doi.org/10.3390/s90705664 - 15 Jul 2009

Cited by 98 | Viewed by 15753

Abstract

In the recent decade, several technology trends have influenced the field of geosciences in significant ways. The first trend is the more readily available technology of ubiquitous wireless communication networks and progress in the development of low-power, short-range radio-based communication networks, the miniaturization [...] Read more.

In the recent decade, several technology trends have influenced the field of geosciences in significant ways. The first trend is the more readily available technology of ubiquitous wireless communication networks and progress in the development of low-power, short-range radio-based communication networks, the miniaturization of computing and storage platforms as well as the development of novel microsensors and sensor materials. All three trends have changed the type of dynamic environmental phenomena that can be detected, monitored and reacted to. Another important aspect is the real-time data delivery of novel platforms today. In this paper, I will survey the field of geosensor networks, and mainly focus on the technology of small-scale geosensor networks, example applications and their feasibility and lessons learnt as well as the current research questions posed by using this technology today. Furthermore, my objective is to investigate how this technology can be embedded in the current landscape of intelligent sensor platforms in the geosciences and identify its place and purpose. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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9 pages, 637 KB

Open AccessArticle

Real-Time Ozone Detection Based on a Microfabricated Quartz Crystal Tuning Fork Sensor

by Rui Wang^1,2, Francis Tsow^1,2, Xuezhi Zhang³, Jhih-Hong Peng², Erica S. Forzani^1,2, Yongsheng Chen^{3,*, †}, John C. Crittenden^{3,*, †}, Hugo Destaillats^3,4,* and Nongjian Tao^1,2,*

¹ Biodesign Institute, Arizona State University, Tempe, AZ, 85287-5801 USA

² Department of Electrical Engineering, Arizona State University, Tempe, AZ, 85287-5801 USA

³ School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, 85287-5801 USA

⁴ Indoor Environment Department, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

^† Current address: Georgia Institute of Technology, School of Civil and Environmental Engineering.

Sensors 2009, 9(7), 5655-5663; https://doi.org/10.3390/s90705655 - 15 Jul 2009

Cited by 24 | Viewed by 11704

Abstract

A chemical sensor for ozone based on an array of microfabricated tuning forks is described. The tuning forks are highly sensitive and stable, with low power consumption and cost. The selective detection is based on the specific reaction of the polymer with ozone. [...] Read more.

A chemical sensor for ozone based on an array of microfabricated tuning forks is described. The tuning forks are highly sensitive and stable, with low power consumption and cost. The selective detection is based on the specific reaction of the polymer with ozone. With a mass detection limit of ~2 pg/mm² and response time of 1 second, the sensor coated with a polymer sensing material can detect ppb-level ozone in air. The sensor is integrated into a miniaturized wearable device containing a detection circuit, filtration, battery and wireless communication chip, which is ideal for personal and microenvironmental chemical exposure monitoring. Full article

(This article belongs to the Special Issue Gas Sensors 2009)

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6 pages, 167 KB

Open AccessArticle

High Temperature Long Period Grating Thermo-Mechanically Written

by Jose Miguel Lazaro^*, Antonio Quintela and Jose Miguel Lopez-Higuera

Photonics Engineering Group, University of Cantabria, Avda. de los Castros S/N, 39005 Santander, Spain

Sensors 2009, 9(7), 5649-5654; https://doi.org/10.3390/s90705649 - 15 Jul 2009

Cited by 4 | Viewed by 10943

Abstract

An optical fiber transducer able to work in high temperature environments is experimentally demonstrated in the laboratory. It is based on a permanent long period grating (LPG) written using a new technique based on a thermo-mechanical approach. Device precision was experimentally checked by [...] Read more.

An optical fiber transducer able to work in high temperature environments is experimentally demonstrated in the laboratory. It is based on a permanent long period grating (LPG) written using a new technique based on a thermo-mechanical approach. Device precision was experimentally checked by means of repetitive thermal cycles between 25 and 950 ºC. In addition device stability was assured by maintaining the temperature in steady state at 800 ºC during 23 hours. Full article

(This article belongs to the Section Chemical Sensors)

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12 pages, 444 KB

Open AccessArticle

MEMS Biomimetic Acoustic Pressure Gradient Sensitive Structure for Sound Source Localization

by Peng An, Weizheng Yuan^* and Sen Ren

Micro and Nano Electro Mechanical System Laboratory, Northwestern Polytechnical University, Xi’an City, Shaanxi Province, 710072, China

Sensors 2009, 9(7), 5637-5648; https://doi.org/10.3390/s90705637 - 15 Jul 2009

Cited by 12 | Viewed by 11050

Abstract

The parasitoid fly Ormia ochracea shows an astonishing localization ability with its tiny hearing organ. A novel MEMS biomimetic acoustic pressure gradient sensitive structure was designed and fabricated by mimicking the mechanically coupled tympana of the fly. Firstly, the analytic representation formulas of [...] Read more.

The parasitoid fly Ormia ochracea shows an astonishing localization ability with its tiny hearing organ. A novel MEMS biomimetic acoustic pressure gradient sensitive structure was designed and fabricated by mimicking the mechanically coupled tympana of the fly. Firstly, the analytic representation formulas of the resultant force and resultant moment of the incoming plane wave acting on the structure were derived. After that, structure modal analysis was performed and the results show that the structure has out-of-phase and in-phase vibration modes, and the corresponding eigenfrequency is decided by the stiffness of vertical torsional beam and horizontal beam respectively. Acoustic-structural coupled analysis was performed and the results show that phase difference and amplitude difference between the responses of the two square diaphragms of the sensitive structure are effectively enlarged through mechanical coupling beam. The phase difference and amplitude difference increase with increasing incident angle and can be used to distinguish the direction of sound arrival. At last, the fabrication process and results of the device is also presented. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)

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37 pages, 1144 KB

Open AccessReview

DNA Sensors with Diamond as a Promising Alternative Transducer Material

by Veronique Vermeeren¹, Sylvia Wenmackers², Patrick Wagner² and Luc Michiels^1,*

¹ Biomedical Research Institute, School for Life Sciences, Hasselt University and Transnationale Universiteit Limburg, Agoralaan, Bldg. C, B-3590 Diepenbeek, Belgium

² Institute for Materials Research, School for Life Sciences, Hasselt University and Transnationale Universiteit Limburg, Wetenschapspark 1, B-3590 Diepenbeek, Belgium

Sensors 2009, 9(7), 5600-5636; https://doi.org/10.3390/s90705600 - 14 Jul 2009

Cited by 55 | Viewed by 14461

Abstract

Bio-electronics is a scientific field coupling the achievements in biology with electronics to obtain higher sensitivity, specificity and speed. Biosensors have played a pivotal role, and many have become established in the clinical and scientific world. They need to be sensitive, specific, fast [...] Read more.

Bio-electronics is a scientific field coupling the achievements in biology with electronics to obtain higher sensitivity, specificity and speed. Biosensors have played a pivotal role, and many have become established in the clinical and scientific world. They need to be sensitive, specific, fast and cheap. Electrochemical biosensors are most frequently cited in literature, often in the context of DNA sensing and mutation analysis. However, many popular electrochemical transduction materials, such as silicon, are susceptible to hydrolysis, leading to loss of bioreceptor molecules from the surface. Hence, increased attention has been shifted towards diamond, which surpasses silicon on many levels. Full article

(This article belongs to the Special Issue DNA Sensors and Biosensors)

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10 pages, 233 KB

Open AccessArticle

Quantitative Analysis of Nucleic Acid Hybridization on Magnetic Particles and Quantum Dot-Based Probes

by Sun Hee Lim^1,*, Felix Bestvater², Philippe Buchy³, Sek Mardy³ and Alexey Dan Chin Yu^1,*

¹ Diagnostics, Institut Pasteur Korea, 696 Sampyeong-dong, Bundang-gu, Seongnam City, Gyeonggi-do, 443-270, Korea

² Cell Biophysics, Institut Pasteur Korea, 696 Sampyeong-dong, Bundang-gu, Seongnam City, Gyeonggi-do, 443-270, Korea

³ Virology Unit, Institut Pasteur in Cambodia, 5, Monivong boulevard, Phnom Penh, Cambodia

Sensors 2009, 9(7), 5590-5599; https://doi.org/10.3390/s90705590 - 14 Jul 2009

Cited by 20 | Viewed by 15042

Abstract

In the present study we describe sandwich design hybridization probes consisting of magnetic particles (MP) and quantum dots (QD) with target DNA, and their application in the detection of avian influenza virus (H5N1) sequences. Hybridization of 25-, 40-, and 100-mer target DNA with [...] Read more.

In the present study we describe sandwich design hybridization probes consisting of magnetic particles (MP) and quantum dots (QD) with target DNA, and their application in the detection of avian influenza virus (H5N1) sequences. Hybridization of 25-, 40-, and 100-mer target DNA with both probes was analyzed and quantified by flow cytometry and fluorescence microscopy on the scale of single particles. The following steps were used in the assay: (i) target selection by MP probes and (ii) target detection by QD probes. Hybridization efficiency between MP conjugated probes and target DNA hybrids was controlled by a fluorescent dye specific for nucleic acids. Fluorescence was detected by flow cytometry to distinguish differences in oligo sequences as short as 25-mer capturing in target DNA and by gel-electrophoresis in the case of QD probes. This report shows that effective manipulation and control of micro- and nanoparticles in hybridization assays is possible. Full article

(This article belongs to the Section Biosensors)

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10 pages, 191 KB

Open AccessArticle

Variation of Cholinesterase-Based Biosensor Sensitivity to Inhibition by Organophosphate Due To Ionizing Radiation

by Miroslav Pohanka^1,* and Miroslav Koch²

¹ Centre for Advanced Studies and Department of Toxicology, Faculty of Military Health Sciences, University of Defense, Trebesska 1575, 50002 Hradec Kralove, Czech Republic

² VF Company, Namesti Miru 50, 679 21 Cerna Hora, Czech Republic

Sensors 2009, 9(7), 5580-5589; https://doi.org/10.3390/s90705580 - 14 Jul 2009

Cited by 1 | Viewed by 10075

Abstract

A cholinesterase based biosensor was constructed in order to assess the effects of ionizing radiation on exposed AChE. Although the primary objective of the experiment was to investigate the effect of ionizing radiation on the activity of the biosensor, no changes in cholinesterase [...] Read more.

A cholinesterase based biosensor was constructed in order to assess the effects of ionizing radiation on exposed AChE. Although the primary objective of the experiment was to investigate the effect of ionizing radiation on the activity of the biosensor, no changes in cholinesterase activity were observed. Current provided by oxidation of thiocholine previously created from acetylthiocholine by enzyme catalyzed reaction was in a range 395–455 nA. No significant influence of radiation on AChE activity was found, despite the current variation. However, a surprising phenomenon was observed when a model organophosphate paraoxon was assayed. Irradiated biosensors seem to be more susceptible to the inhibitory effects of paraoxon. Control biosensors provided a 94 ± 5 nA current after exposure to 1 ppm paraoxon. The biosensors irradiated by a 5 kGy radiation dose and exposed to paraoxon provided a current of 49 ± 6 nA. Irradiation by doses ranging from 5 mGy to 100 kGy were investigated and the mentioned effect was confirmed at doses above 50 Gy. After the first promising experiments, biosensors irradiated by 5 kGy were used for calibration on paraoxon and compared with the control biosensors. Limits of detection 2.5 and 3.8 ppb were achieved for irradiated and non-irradiated biosensors respectively. The overall impact of this effect is discussed. Full article

(This article belongs to the Special Issue Tissue, Cell and Molecular Bioelectrochemistry - New Trends and Approaches)

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22 pages, 656 KB

Open AccessArticle

An Improved Cloud Classification Algorithm for China’s FY-2C Multi-Channel Images Using Artificial Neural Network

by Yu Liu^1,2, Jun Xia^1,*, Chun-Xiang Shi³ and Yang Hong⁴

¹ Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China

² Graduate School of the Chinese Academy of Science, CAS, Beijing,100039, China

³ National Satellite Meteorological Center, Beijing 100081, China

⁴ School of Civil Engineering and Environmental Sciences, University of Oklahoma, National Weather Center Suite 3630, Norman, OK 73019, USA

Sensors 2009, 9(7), 5558-5579; https://doi.org/10.3390/s90705558 - 14 Jul 2009

Cited by 69 | Viewed by 16825

Abstract

The crowning objective of this research was to identify a better cloud classification method to upgrade the current window-based clustering algorithm used operationally for China’s first operational geostationary meteorological satellite FengYun-2C (FY-2C) data. First, the capabilities of six widely-used Artificial Neural Network (ANN) [...] Read more.

The crowning objective of this research was to identify a better cloud classification method to upgrade the current window-based clustering algorithm used operationally for China’s first operational geostationary meteorological satellite FengYun-2C (FY-2C) data. First, the capabilities of six widely-used Artificial Neural Network (ANN) methods are analyzed, together with the comparison of two other methods: Principal Component Analysis (PCA) and a Support Vector Machine (SVM), using 2864 cloud samples manually collected by meteorologists in June, July, and August in 2007 from three FY-2C channel (IR1, 10.3-11.3 μm; IR2, 11.5-12.5 μm and WV 6.3-7.6 μm) imagery. The result shows that: (1) ANN approaches, in general, outperformed the PCA and the SVM given sufficient training samples and (2) among the six ANN networks, higher cloud classification accuracy was obtained with the Self-Organizing Map (SOM) and Probabilistic Neural Network (PNN). Second, to compare the ANN methods to the present FY-2C operational algorithm, this study implemented SOM, one of the best ANN network identified from this study, as an automated cloud classification system for the FY-2C multi-channel data. It shows that SOM method has improved the results greatly not only in pixel-level accuracy but also in cloud patch-level classification by more accurately identifying cloud types such as cumulonimbus, cirrus and clouds in high latitude. Findings of this study suggest that the ANN-based classifiers, in particular the SOM, can be potentially used as an improved Automated Cloud Classification Algorithm to upgrade the current window-based clustering method for the FY-2C operational products. Full article

(This article belongs to the Special Issue Neural Networks and Sensors)

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24 pages, 490 KB

Open AccessReview

Recent Development of Nano-Materials Used in DNA Biosensors

by Kai Xu^1,2, Junran Huang¹, Zunzhong Ye¹, Yibin Ying^1,* and Yanbin Li³

¹ School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang Province, China

² Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences; Key Laboratory of Biofuels, Chinese Academy of Sciences, Qingdao, Shandong Province, 266101, China

³ Department of Biological & Agricultural Engineering, University of Arkansas, Fayetteville, AR 72701, USA

Sensors 2009, 9(7), 5534-5557; https://doi.org/10.3390/s90705534 - 14 Jul 2009

Cited by 138 | Viewed by 18683

Abstract

As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has [...] Read more.

As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has been considerable interest in using nano-materials for DNA biosensors. Because of their high surface-to-volume ratios and excellent biological compatibilities, nano-materials could be used to increase the amount of DNA immobilization; moreover, DNA bound to nano-materials can maintain its biological activity. Alternatively, signal amplification by labeling a targeted analyte with nano-materials has also been reported for DNA biosensors in many papers. This review summarizes the applications of various nano-materials for DNA biosensors during past five years. We found that nano-materials of small sizes were advantageous as substrates for DNA attachment or as labels for signal amplification; and use of two or more types of nano-materials in the biosensors could improve their overall quality and to overcome the deficiencies of the individual nano-components. Most current DNA biosensors require the use of polymerase chain reaction (PCR) in their protocols. However, further development of nano-materials with smaller size and/or with improved biological and chemical properties would substantially enhance the accuracy, selectivity and sensitivity of DNA biosensors. Thus, DNA biosensors without PCR amplification may become a reality in the foreseeable future. Full article

(This article belongs to the Section Biosensors)

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13 pages, 1021 KB

Open AccessArticle

An Algorithm for Cold Patch Detection in the Sea off Northeast Taiwan Using Multi-Sensor Data

by Yu-Hsin Cheng, Chung-Ru Ho^*, Zhe-Wen Zheng, Yung-Hsiang Lee and Nan-Jung Kuo

Department of Marine Environmental Informatics, National Taiwan Ocean University / 2 Pei-Ning Road, Keelung 20224, Taiwan

Sensors 2009, 9(7), 5521-5533; https://doi.org/10.3390/s90705521 - 13 Jul 2009

Cited by 19 | Viewed by 10991

Abstract

Multi-sensor data from different satellites are used to identify an upwelling area in the sea off northeast Taiwan. Sea surface temperature (SST) data derived from infrared and microwave, as well as sea surface height anomaly (SSHA) data derived from satellite altimeters are used [...] Read more.

Multi-sensor data from different satellites are used to identify an upwelling area in the sea off northeast Taiwan. Sea surface temperature (SST) data derived from infrared and microwave, as well as sea surface height anomaly (SSHA) data derived from satellite altimeters are used for this study. An integration filtering algorithm based on SST data is developed for detecting the cold patch induced by the upwelling. The center of the cold patch is identified by the maximum negative deviation relative to the spatial mean of a SST image within the study area and its climatological mean of each pixel. The boundary of the cold patch is found by the largest SST gradient. The along track SSHA data derived from satellite altimeters are then used to verify the detected cold patch. Applying the detecting algorithm, spatial and temporal characteristics and variations of the cold patch are revealed. The cold patch has an average area of 1.92 ´ 10⁴ km². Its occurrence frequencies are high from June to October and reach a peak in July. The mean SST of the cold patch is 23.8 °C. In addition to the annual and the intraseasonal fluctuation with main peak centered at 60 days, the cold patch also has a variation period of about 4.7 years in the interannual timescale. This implies that the Kuroshio variations and long-term and large scale processes playing roles in modifying the cold patch occurrence frequency. Full article

(This article belongs to the Special Issue Sensor Algorithms)

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18 pages, 648 KB

Open AccessReview

Electroanalytical Sensors and Devices for Multiplexed Detection of Foodborne Pathogen Microorganisms

by María Pedrero

, Susana Campuzano

and José M. Pingarrón^*

Departamento de Química Analítica. Facultad de Ciencias Químicas. Universidad Complutense de Madrid. E-28040 Madrid, Spain

Sensors 2009, 9(7), 5503-5520; https://doi.org/10.3390/s90705503 - 13 Jul 2009

Cited by 62 | Viewed by 15814

Abstract

The detection and identification of pathogen microorganisms still rely on conventional culturing techniques, which are not suitable for on-site monitoring. Therefore, a great research challenge in this field is focused on the need to develop rapid, reliable, specific, and sensitive methods to detect [...] Read more.

The detection and identification of pathogen microorganisms still rely on conventional culturing techniques, which are not suitable for on-site monitoring. Therefore, a great research challenge in this field is focused on the need to develop rapid, reliable, specific, and sensitive methods to detect these bacteria at low cost. Moreover, the growing interest in biochip development for large scale screening analysis implies improved miniaturization, reduction of analysis time and cost, and multi-analyte detection, which has nowadays become a crucial challenge. This paper reviews multiplexed foodborne pathogen microorganisms detection methods based on electrochemical sensors incorporating microarrays and other platforms. These devices usually involve antibody-antigen and DNA hybridization specific interactions, although other approaches such as the monitoring of oxygen consumption are also considered. Full article

(This article belongs to the Special Issue Pathogen Sensors)

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10 pages, 510 KB

Open AccessArticle

Sharing Sensor Data with SensorSA and Cascading Sensor Observation Service

by Denis Havlik^*, Thomas Bleier and Gerald Schimak

Austrian Institute of Technology, Donau-City Straße 1, A1220 Vienna, Austria

Sensors 2009, 9(7), 5493-5502; https://doi.org/10.3390/s90705493 - 10 Jul 2009

Cited by 14 | Viewed by 11453

Abstract

The SANY IP consortium (http://www.sany-ip.eu) has recently developed several interesting service prototypes that extend the usability of the Open Geospatial Consortium “Sensor Web Enablement” (OGC SWE) architecture. One such service prototype, developed by the Austrian Research Centers, is the “cascading SOS” (SOS-X). SOS-X [...] Read more.

The SANY IP consortium (http://www.sany-ip.eu) has recently developed several interesting service prototypes that extend the usability of the Open Geospatial Consortium “Sensor Web Enablement” (OGC SWE) architecture. One such service prototype, developed by the Austrian Research Centers, is the “cascading SOS” (SOS-X). SOS-X is a client to the underlying OGC Sensor Observation service(s) (SOS). It provides alternative access routes to users (or services) interested in accessing data. In addition to a simple cascading, SOS-X can re-format, re-organize, and merge data from several sources into a single SOS offering. Thanks to the built-in “Formula 3” prototype, a kind of time series library, SOS-X will be enabled to derive new data sets on the fly executing arbitrary algebraic operations on one or more data input streams. This article will discuss the SOS-X development status (focusing at end of 2008), further development agenda in year 2009, and possibilities for using the SOS-X outside of the SANY IP. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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16 pages, 1288 KB

Open AccessArticle

Remote Sensor for Spatial Measurements by Using Optical Scanning

by Oleg Sergiyenko^1,*, Wilmar Hernandez², Vira Tyrsa³, Luis Felipe Devia Cruz¹, Oleg Starostenko⁴ and Mario Peña-Cabrera⁵

¹ Engineering Institute, Autonomous University of Baja California, Calle de la Normal S/N, col. Insurgentes, Mexicali, Baja California, Mexico

² Department of Circuits and Systems in the EUIT de Telecomunicación at the Universidad Politécnica de Madrid (UPM), Campus Sur UPM, Ctra. Valencia km 7, Madrid 28031, Spain

³ Universidad Politécnica de Baja California, Mexico

⁴ Universidad de Las Americas, Puebla, Mexico

⁵ Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas (IIMAS), Ciudad Universitaria, Univesidad Nacional Autónoma de México, D.F. CP 04510, Mexico

Sensors 2009, 9(7), 5477-5492; https://doi.org/10.3390/s90705477 - 10 Jul 2009

Cited by 34 | Viewed by 11913

Abstract

In this paper, we propose a low-cost contact-free measurement system for both 3-D data acquisition and fast surface parameter registration by digitized points. Despite the fact that during the last decade several approaches for both contact-free measurement techniques aimed at carrying out object [...] Read more.

In this paper, we propose a low-cost contact-free measurement system for both 3-D data acquisition and fast surface parameter registration by digitized points. Despite the fact that during the last decade several approaches for both contact-free measurement techniques aimed at carrying out object surface recognition and 3-D object recognition have been proposed, they often still require complex and expensive equipment. Therefore, alternative low cost solutions are in great demand. Here, two low-cost solutions to the above-mentioned problem are presented. These are two examples of practical applications of the novel passive optical scanning system presented in this paper. Full article

(This article belongs to the Section Remote Sensors)

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17 pages, 536 KB

Open AccessArticle

A MEMS-Based Flow Rate and Flow Direction Sensing Platform with Integrated Temperature Compensation Scheme

by Rong-Hua Ma¹, Dung-An Wang², Tzu-Han Hsueh³ and Chia-Yen Lee^4,*

¹ Department of Mechanical Engineering, Chinese Military Academy, Kaohsiung 830, Taiwan

² Institute of Precision Engineering, National Chung Hsing University, Taichung 402, Taiwan

³ Department of Mechanical and Automation Engineering, Da-Yeh University, Changhua 515, Taiwan

⁴ Department of Materials Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan

Sensors 2009, 9(7), 5460-5476; https://doi.org/10.3390/s90705460 - 9 Jul 2009

Cited by 45 | Viewed by 16348

Abstract

This study develops a MEMS-based low-cost sensing platform for sensing gas flow rate and flow direction comprising four silicon nitride cantilever beams arranged in a cross-form configuration, a circular hot-wire flow meter suspended on a silicon nitride membrane, and an integrated resistive temperature [...] Read more.

This study develops a MEMS-based low-cost sensing platform for sensing gas flow rate and flow direction comprising four silicon nitride cantilever beams arranged in a cross-form configuration, a circular hot-wire flow meter suspended on a silicon nitride membrane, and an integrated resistive temperature detector (RTD). In the proposed device, the flow rate is inversely derived from the change in the resistance signal of the flow meter when exposed to the sensed air stream. To compensate for the effects of the ambient temperature on the accuracy of the flow rate measurements, the output signal from the flow meter is compensated using the resistance signal generated by the RTD. As air travels over the surface of the cross-form cantilever structure, the upstream cantilevers are deflected in the downward direction, while the downstream cantilevers are deflected in the upward direction. The deflection of the cantilever beams causes a corresponding change in the resistive signals of the piezoresistors patterned on their upper surfaces. The amount by which each beam deflects depends on both the flow rate and the orientation of the beam relative to the direction of the gas flow. Thus, following an appropriate compensation by the temperature-corrected flow rate, the gas flow direction can be determined through a suitable manipulation of the output signals of the four piezoresistors. The experimental results have confirmed that the resulting variation in the output signals of the integrated sensors can be used to determine not only the ambient temperature and the velocity of the air flow, but also its direction relative to the sensor with an accuracy of ± 7.5^o error. Full article

(This article belongs to the Special Issue Sensor Configuration and Smart Sensors)

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14 pages, 159 KB

Open AccessReview

Sensing Mercury for Biomedical and Environmental Monitoring

by Paul D. Selid¹, Hanying Xu², E. Michael Collins³, Marla Striped Face-Collins³ and Julia Xiaojun Zhao^1,*

¹ Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA

² Environmental Analytical Research Laboratory, University of North Dakota, Grand Forks, ND 58202, USA

³ Tribal Environmental Science Department, United Tribes Technical College, Bismarck, ND 58504, USA

Sensors 2009, 9(7), 5446-5459; https://doi.org/10.3390/s90705446 - 9 Jul 2009

Cited by 181 | Viewed by 21759

Abstract

Mercury is a very toxic element that is widely spread in the atmosphere, lithosphere, and surface water. Concentrated mercury poses serious problems to human health, as bioaccumulation of mercury within the brain and kidneys ultimately leads to neurological diseases. To control mercury pollution [...] Read more.

Mercury is a very toxic element that is widely spread in the atmosphere, lithosphere, and surface water. Concentrated mercury poses serious problems to human health, as bioaccumulation of mercury within the brain and kidneys ultimately leads to neurological diseases. To control mercury pollution and reduce mercury damage to human health, sensitive determination of mercury is important. This article summarizes some current sensors for the determination of both abiotic and biotic mercury. A wide array of sensors for monitoring mercury is described, including biosensors and chemical sensors, while piezoelectric and microcantilever sensors are also described. Additionally, newly developed nanomaterials offer great potential for fabricating novel mercury sensors. Some of the functional fluorescent nanosensors for the determination of mercury are covered. Afterwards, the in vivo determination of mercury and the characterization of different forms of mercury are discussed. Finally, the future direction for mercury detection is outlined, suggesting that nanomaterials may provide revolutionary tools in biomedical and environmental monitoring of mercury. Full article

(This article belongs to the Special Issue Fluorescent Chemosensors)

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23 pages, 1634 KB

Open AccessArticle

Translocation Biosensors – Cellular System Integrators to Dissect CRM1-Dependent Nuclear Export by Chemicogenomics

by Verena Fetz¹, Shirley K. Knauer^1,*, Carolin Bier¹, Jens Peter Von Kries² and Roland H. Stauber^1,*

¹ Department of Molecular and Cellular Oncology, University of Mainz, Langenbeckstrasse 1, 55101 Mainz, Germany

² Leibniz-Institut für Molekulare Pharmakologie, Berlin, Robert-Rössle-Str. 10, 13125 Berlin, Germany

Sensors 2009, 9(7), 5423-5445; https://doi.org/10.3390/s90705423 - 9 Jul 2009

Cited by 30 | Viewed by 14857

Abstract

Fluorescent protein biosensors are powerful cellular systems biology tools for dissecting the complexity of cellular processes with high spatial and temporal resolution. As regulated nucleo-cytoplasmic transport is crucial for the modulation of numerous (patho)physiological cellular responses, a detailed understanding of its molecular mechanism [...] Read more.

Fluorescent protein biosensors are powerful cellular systems biology tools for dissecting the complexity of cellular processes with high spatial and temporal resolution. As regulated nucleo-cytoplasmic transport is crucial for the modulation of numerous (patho)physiological cellular responses, a detailed understanding of its molecular mechanism would open up novel options for a rational manipulation of the cell. In contrast to genetic approaches, we here established and employed high-content cellular translocation biosensors applicable for dissecting nuclear export by chemicogenomics. A431 cell lines, stably expressing a translocation biosensor composed of glutathione S-transferase, GFP and a rational combination of nuclear import and export signals, were engineered by antibiotic selection and flow cytometry sorting. Using an optimized nuclear translocation algorithm, the translocation response could be robustly quantified on the Cellomics Arrayscan^® VTI platform. Subsequent to assay optimization, the assay was developed into a higher density 384-well format high-content assay and employed for the screening of the 17K ChemBioNet compound collection. This library was selected on the basis of a genetic algorithm used to identify maximum common chemical substructures in a database of annotated bioactive molecules and hence, is well-placed in the chemical space covered by bioactive compounds. Automated multiparameter data analysis combined with visual inspection allowed us to identify and to rationally discriminate true export inhibitors from false positives, which included fluorescent compounds or cytotoxic substances that dramatically affected the cellular morphology. A total of 120 potential hit compounds were selected for Cellomics Arrayscan^® VTI based rescreening. The export inhibitory activity of 20 compounds effective at concentrations < 25 μM were confirmed by fluorescence microscopy in several cell lines. Interestingly, kinetic analysis allowed the identification of inhibitors capable to interfere with the export receptor CRM1-mediated nuclear export not only in an irreversible, but also in a reversible fashion. In sum, exploitation of biosensor based screening allows the identification of chemicogenomic tools applicable for dissecting nucleo-cytoplasmic transport in living cells. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Germany)

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33 pages, 1436 KB

Open AccessArticle

Adjacency Matrix-Based Transmit Power Allocation Strategies in Wireless Sensor Networks

by Luca Consolini¹, Paolo Medagliani^2,* and Gianluigi Ferrari²

¹ Department of Information Engineering, University of Parma, viale G.P. Usberti 181/A, Parma, Italy

² Wireless Ad-hoc and Sensor Networks (WASN) Laboratory, Department of Information Engineering, University of Parma, viale G.P. Usberti 181/A, Parma, Italy

Sensors 2009, 9(7), 5390-5422; https://doi.org/10.3390/s90705390 - 9 Jul 2009

Cited by 7 | Viewed by 12981

Abstract

In this paper, we present an innovative transmit power control scheme, based on optimization theory, for wireless sensor networks (WSNs) which use carrier sense multiple access (CSMA) with collision avoidance (CA) as medium access control (MAC) protocol. In particular, we focus on schemes [...] Read more.

In this paper, we present an innovative transmit power control scheme, based on optimization theory, for wireless sensor networks (WSNs) which use carrier sense multiple access (CSMA) with collision avoidance (CA) as medium access control (MAC) protocol. In particular, we focus on schemes where several remote nodes send data directly to a common access point (AP). Under the assumption of finite overall network transmit power and low traffic load, we derive the optimal transmit power allocation strategy that minimizes the packet error rate (PER) at the AP. This approach is based on modeling the CSMA/CA MAC protocol through a finite state machine and takes into account the network adjacency matrix, depending on the transmit power distribution and determining the network connectivity. It will be then shown that the transmit power allocation problem reduces to a convex constrained minimization problem. Our results show that, under the assumption of low traffic load, the power allocation strategy, which guarantees minimal delay, requires the maximization of network connectivity, which can be equivalently interpreted as the maximization of the number of non-zero entries of the adjacency matrix. The obtained theoretical results are confirmed by simulations for unslotted Zigbee WSNs. Full article

(This article belongs to the Special Issue Wireless Sensor Technologies and Applications)

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11 pages, 362 KB

Open AccessArticle

Biophysical Micromixer

by Chin-Tsan Wang^*, Yuh-Chung Hu and Tzu-Yang Hu

Department of Mechanical and Electromechanical Engineering, Center of Green Technology, National I-Lan University, I Lan, 26047, Taiwan

Sensors 2009, 9(7), 5379-5389; https://doi.org/10.3390/s90705379 - 8 Jul 2009

Cited by 21 | Viewed by 10814

Abstract

In this study a biophysical passive micromixer with channel anamorphosis in a space of 370 mm, which is shorter than traditional passive micromixers, could be created by mimicing features of vascular flow networks and executed with Reynolds numbers ranging from 1 to 90. [...] Read more.

In this study a biophysical passive micromixer with channel anamorphosis in a space of 370 mm, which is shorter than traditional passive micromixers, could be created by mimicing features of vascular flow networks and executed with Reynolds numbers ranging from 1 to 90. Split and recombination (SAR) was the main mixing method for enhancing the convection effect and promoting the mixing performance in the biophysical channel. The 2D numerical results reveal that good mixing efficiency of the mixer was possible, with ε_mixing = 0.876 at Reynolds number ration Re_r= 0.85. Generally speaking, increasing the Reynolds number will enhance the mixing. In addition, the sidewall effect will influence the mixing performance and an optimal mixing performance with ε_mixing = 0.803 will occur at an aspect ratio of AR = 2. These findings will be useful for enhancing mixing performance for passive micromixers. Full article

(This article belongs to the Section Chemical Sensors)

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11 pages, 659 KB

Open AccessReview

Label-Free Electrical Detection Using Carbon Nanotube-Based Biosensors

by Kenzo Maehashi^* and Kazuhiko Matsumoto

The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan

Sensors 2009, 9(7), 5368-5378; https://doi.org/10.3390/s90705368 - 8 Jul 2009

Cited by 93 | Viewed by 18021

Abstract

Label-free detections of biomolecules have attracted great attention in a lot of life science fields such as genomics, clinical diagnosis and practical pharmacy. In this article, we reviewed amperometric and potentiometric biosensors based on carbon nanotubes (CNTs). In amperometric detections, CNT-modified electrodes were [...] Read more.

Label-free detections of biomolecules have attracted great attention in a lot of life science fields such as genomics, clinical diagnosis and practical pharmacy. In this article, we reviewed amperometric and potentiometric biosensors based on carbon nanotubes (CNTs). In amperometric detections, CNT-modified electrodes were used as working electrodes to significantly enhance electroactive surface area. In contrast, the potentiometric biosensors were based on aptamer-modified CNT field-effect transistors (CNTFETs). Since aptamers are artificial oligonucleotides and thus are smaller than the Debye length, proteins can be detected with high sensitivity. In this review, we discussed on the technology, characteristics and developments for commercialization in label-free CNT-based biosensors. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Japan)

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17 pages, 331 KB

Open AccessArticle

Multivalent Anchoring and Oriented Display of Single-Domain Antibodies on Cellulose

by Greg Hussack^1,2, Yan Luo^1,#, Linda Veldhuis³, J. Christopher Hall³, Jamshid Tanha^1,2,3 and Roger MacKenzie^1,3,*

¹ Institute for Biological Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, Canada, K1A 0R6

² Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada, K1H 8M5

³ Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada, N1G 2W1

^# Present address: Caprotec Bioanalytics GmbH, Volmerstr 5, 12489, Berlin, Germany

Sensors 2009, 9(7), 5351-5367; https://doi.org/10.3390/s90705351 - 7 Jul 2009

Cited by 40 | Viewed by 14230

Abstract

Antibody engineering has allowed for the rapid generation of binding agents against virtually any antigen of interest, predominantly for therapeutic applications. Considerably less attention has been given to the development of diagnostic reagents and biosensors using engineered antibodies. Recently, we produced a novel [...] Read more.

Antibody engineering has allowed for the rapid generation of binding agents against virtually any antigen of interest, predominantly for therapeutic applications. Considerably less attention has been given to the development of diagnostic reagents and biosensors using engineered antibodies. Recently, we produced a novel pentavalent bispecific antibody (i.e., decabody) by pentamerizing two single-domain antibodies (sdAbs) through the verotoxin B subunit (VTB) and found both fusion partners to be functional. Using a similar approach, we have engineered a bispecific pentameric fusion protein consisting of five sdAbs and five cellulose-binding modules (CBMs) linked via VTB. To find an optimal design format, we constructed six bispecific pentamers consisting of three different CBMs, fused to the Staphylococcus aureus-specific human sdAb HVHP428, in both orientations. One bispecific pentamer, containing an N-terminal CBM9 and C-terminal HVHP428, was soluble, non-aggregating, and did not degrade upon storage at 4 ºC for over six months. This molecule was dually functional as it bound to cellulose-based filters as well as S. aureus cells. When impregnated in cellulose filters, the bispecific pentamer recognized S. aureus cells in a flow-through detection assay. The ability of pentamerized CBMs to bind cellulose may form the basis of an immobilization platform for multivalent display of high-avidity binding reagents on cellulosic filters for sensing of pathogens, biomarkers and environmental pollutants. Full article

(This article belongs to the Special Issue Pathogen Sensors)

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12 pages, 128 KB

Open AccessArticle

Metaheuristic Based Scheduling Meta-Tasks in Distributed Heterogeneous Computing Systems

by Hesam Izakian¹, Ajith Abraham^2,3,* and Václav Snášel^2,4

¹ Islamic Azad University, Ramsar Branch, Ramsar, Iran

² Machine Intelligence Research Labs (MIR Labs), Auburn, Washington 98071-2259, USA

³ Norwegian Center of Excellence, Center of Excellence for Quantifiable Quality of Service, Norwegian University of Science and Technology, O.S. Bragstads plass 2E, N-7491 Trondheim, Norway

⁴ Faculty of Electrical Engineering and Computer Science VSB-Technical University of Ostrava, Czech Republic

Sensors 2009, 9(7), 5339-5350; https://doi.org/10.3390/s90705339 - 7 Jul 2009

Cited by 32 | Viewed by 12576

Abstract

Scheduling is a key problem in distributed heterogeneous computing systems in order to benefit from the large computing capacity of such systems and is an NP-complete problem. In this paper, we present a metaheuristic technique, namely the Particle Swarm Optimization (PSO) algorithm, for [...] Read more.

Scheduling is a key problem in distributed heterogeneous computing systems in order to benefit from the large computing capacity of such systems and is an NP-complete problem. In this paper, we present a metaheuristic technique, namely the Particle Swarm Optimization (PSO) algorithm, for this problem. PSO is a population-based search algorithm based on the simulation of the social behavior of bird flocking and fish schooling. Particles fly in problem search space to find optimal or near-optimal solutions. The scheduler aims at minimizing makespan, which is the time when finishes the latest task. Experimental studies show that the proposed method is more efficient and surpasses those of reported PSO and GA approaches for this problem. Full article

(This article belongs to the Section Chemical Sensors)

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