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Sensors, Volume 9, Issue 7 (July 2009), Pages 5040-5877

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Open AccessArticle LoWMob: Intra-PAN Mobility Support Schemes for 6LoWPAN
Sensors 2009, 9(7), 5844-5877; https://doi.org/10.3390/s90705844
Received: 22 May 2009 / Revised: 23 June 2009 / Accepted: 25 June 2009 / Published: 23 July 2009
Cited by 53 | PDF Full-text (1585 KB) | HTML Full-text | XML Full-text
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,
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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)
Open AccessArticle Fundamentals of in Situ Digital Camera Methodology for Water Quality Monitoring of Coast and Ocean
Sensors 2009, 9(7), 5825-5843; https://doi.org/10.3390/s90705825
Received: 8 May 2009 / Revised: 16 June 2009 / Accepted: 15 July 2009 / Published: 22 July 2009
Cited by 12 | PDF Full-text (596 KB) | HTML Full-text | XML Full-text
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
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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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Open AccessArticle Evanescent Wave Fiber Optic Biosensor for Salmonella Detection in Food
Sensors 2009, 9(7), 5810-5824; https://doi.org/10.3390/s90705810
Received: 8 May 2009 / Revised: 15 July 2009 / Accepted: 17 July 2009 / Published: 21 July 2009
Cited by 42 | PDF Full-text (128 KB) | HTML Full-text | XML Full-text
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
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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 102 cfu/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)
Open AccessReview Waveguide-Based Biosensors for Pathogen Detection
Sensors 2009, 9(7), 5783-5809; https://doi.org/10.3390/s90705783
Received: 4 June 2009 / Revised: 13 July 2009 / Accepted: 13 July 2009 / Published: 21 July 2009
Cited by 89 | PDF Full-text (718 KB) | HTML Full-text | XML Full-text
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,
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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)
Open AccessArticle Potential of ILRIS3D Intensity Data for Planar Surfaces Segmentation
Sensors 2009, 9(7), 5770-5782; https://doi.org/10.3390/s90705770
Received: 27 April 2009 / Revised: 5 June 2009 / Accepted: 15 July 2009 / Published: 20 July 2009
Cited by 6 | PDF Full-text (752 KB) | HTML Full-text | XML Full-text | Supplementary Files
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
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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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Open AccessReview Surface Generated Acoustic Wave Biosensors for the Detection of Pathogens: A Review
Sensors 2009, 9(7), 5740-5769; https://doi.org/10.3390/s90705740
Received: 31 May 2009 / Revised: 7 July 2009 / Accepted: 14 July 2009 / Published: 20 July 2009
Cited by 98 | PDF Full-text (519 KB) | HTML Full-text | XML Full-text
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
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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)
Open AccessArticle Adaptive Momentum-Based Motion Detection Approach and Its Application on Handoff in Wireless Networks
Sensors 2009, 9(7), 5715-5739; https://doi.org/10.3390/s90705715
Received: 15 June 2009 / Revised: 3 July 2009 / Accepted: 15 July 2009 / Published: 17 July 2009
Cited by 6 | PDF Full-text (838 KB) | HTML Full-text | XML Full-text
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)
Open AccessArticle Antioxidant Activity and Total Phenolic and Flavonoid Contents of Hieracium pilosella L. Extracts
Sensors 2009, 9(7), 5702-5714; https://doi.org/10.3390/s90705702
Received: 25 May 2009 / Revised: 26 June 2009 / Accepted: 15 July 2009 / Published: 16 July 2009
Cited by 80 | PDF Full-text (567 KB) | HTML Full-text | XML Full-text
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
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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)
Open AccessArticle Object-Based Integration of Photogrammetric and LiDAR Data for Automated Generation of Complex Polyhedral Building Models
Sensors 2009, 9(7), 5679-5701; https://doi.org/10.3390/s90705679
Received: 8 June 2009 / Revised: 7 July 2009 / Accepted: 7 July 2009 / Published: 15 July 2009
Cited by 32 | PDF Full-text (2652 KB) | HTML Full-text | XML Full-text
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
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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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Open AccessArticle A Survey of Geosensor Networks: Advances in Dynamic Environmental Monitoring
Sensors 2009, 9(7), 5664-5678; https://doi.org/10.3390/s90705664
Received: 7 July 2009 / Revised: 10 July 2009 / Accepted: 13 July 2009 / Published: 15 July 2009
Cited by 67 | PDF Full-text (274 KB) | HTML Full-text | XML Full-text
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
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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)
Open AccessArticle Real-Time Ozone Detection Based on a Microfabricated Quartz Crystal Tuning Fork Sensor
Sensors 2009, 9(7), 5655-5663; https://doi.org/10.3390/s90705655
Received: 5 June 2009 / Revised: 8 July 2009 / Accepted: 14 July 2009 / Published: 15 July 2009
Cited by 11 | PDF Full-text (637 KB) | HTML Full-text | XML Full-text
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.
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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)
Open AccessArticle High Temperature Long Period Grating Thermo-Mechanically Written
Sensors 2009, 9(7), 5649-5654; https://doi.org/10.3390/s90705649
Received: 22 June 2009 / Revised: 7 July 2009 / Accepted: 7 July 2009 / Published: 15 July 2009
Cited by 4 | PDF Full-text (167 KB) | HTML Full-text | XML Full-text
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
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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)
Open AccessArticle MEMS Biomimetic Acoustic Pressure Gradient Sensitive Structure for Sound Source Localization
Sensors 2009, 9(7), 5637-5648; https://doi.org/10.3390/s90705637
Received: 14 May 2009 / Revised: 17 June 2009 / Accepted: 6 July 2009 / Published: 15 July 2009
Cited by 6 | PDF Full-text (444 KB) | HTML Full-text | XML Full-text
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
Open AccessReview DNA Sensors with Diamond as a Promising Alternative Transducer Material
Sensors 2009, 9(7), 5600-5636; https://doi.org/10.3390/s90705600
Received: 5 June 2009 / Revised: 2 July 2009 / Accepted: 3 July 2009 / Published: 14 July 2009
Cited by 25 | PDF Full-text (1144 KB) | HTML Full-text | XML Full-text
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)
Open AccessArticle Quantitative Analysis of Nucleic Acid Hybridization on Magnetic Particles and Quantum Dot-Based Probes
Sensors 2009, 9(7), 5590-5599; https://doi.org/10.3390/s90705590
Received: 17 June 2009 / Revised: 8 July 2009 / Accepted: 13 July 2009 / Published: 14 July 2009
Cited by 15 | PDF Full-text (233 KB) | HTML Full-text | XML Full-text
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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