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Chemosensors, Volume 7, Issue 1 (March 2019)

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Cover Story (view full-size image) Mycotoxins are secondary fungal metabolites that pose a serious threat to food safety. Conventional [...] Read more.
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Open AccessArticle Handheld Enzymatic Luminescent Biosensor for Rapid Detection of Heavy Metals in Water Samples
Chemosensors 2019, 7(1), 16; https://doi.org/10.3390/chemosensors7010016
Received: 15 February 2019 / Revised: 18 March 2019 / Accepted: 19 March 2019 / Published: 26 March 2019
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Abstract
Enzymatic luminescent systems are a promising tool for rapid detection of heavy metals ions for water quality assessment. Nevertheless, their widespread use is limited by the lack of test procedure automation and available sensitive handheld luminometers. Herein we describe integration of disposable microfluidic [...] Read more.
Enzymatic luminescent systems are a promising tool for rapid detection of heavy metals ions for water quality assessment. Nevertheless, their widespread use is limited by the lack of test procedure automation and available sensitive handheld luminometers. Herein we describe integration of disposable microfluidic chips for bioluminescent enzyme-inhibition based assay with a handheld luminometer, which detection system is based on a thermally stabilized silicon photomultiplier (SiPM). Microfluidic chips were made of poly(methyl methacrylate) by micro-milling method and sealed using a solvent bonding technique. The composition of the bioluminescent system in microfluidic chip was optimized to achieve higher luminescence intensity and storage time. Results indicate that developed device provided comparable sensitivity with bench-scale PMT-based commercial luminometers. Limit of detection for copper (II) sulfate reached 2.5 mg/L for developed biosensor. Hereby we proved the concept of handheld enzymatic optical biosensors with disposable chips for bioassay. The proposed biosensor can be used as an early warning field-deployable system for rapid detection of heavy metals salts and other toxic chemicals, which affect bioluminescent signal of enzymatic reaction. Full article
(This article belongs to the Special Issue Chemical Sensors for Heavy Metals/Toxin Detection)
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Open AccessArticle An Effect of the Space Dimension of Electron Fermi Gas upon the Spin Ordering in Clusters and Nanoparticles
Chemosensors 2019, 7(1), 15; https://doi.org/10.3390/chemosensors7010015
Received: 30 January 2019 / Revised: 10 March 2019 / Accepted: 12 March 2019 / Published: 25 March 2019
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Abstract
Herein, the collective effects of spin polarization in a degenerate electron gas of an arbitrary space dimension are discussed. We consider these low-dimensional systems in light of potential wells (rectangular or cylindrical), and as a two- or one-dimensional oscillator system with the second [...] Read more.
Herein, the collective effects of spin polarization in a degenerate electron gas of an arbitrary space dimension are discussed. We consider these low-dimensional systems in light of potential wells (rectangular or cylindrical), and as a two- or one-dimensional oscillator system with the second (and third) spatial dimension proportional to the oscillator’s length. The concept of “intermediate” sizes ν = 6, 5, 4 corresponding to the quasi-low dimensions ν* = 0, 1, 2, contrary to “pure” space dimensions ν = 1, 2 is introduced. A general effect of the space dimension upon the spontaneous polarization in electron Fermi gas is detected. Full article
(This article belongs to the Special Issue Selected Papers from the N.I.C.E. 2018 Conference)
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Open AccessArticle Electrochemical Glucose Quantification as a Strategy for Ethanolic Fermentation Monitoring
Chemosensors 2019, 7(1), 14; https://doi.org/10.3390/chemosensors7010014
Received: 23 January 2019 / Revised: 7 March 2019 / Accepted: 12 March 2019 / Published: 15 March 2019
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Abstract
The possibility of using an electrochemical biosensor, using screen-printed electrodes modified with a carbonaceous material and a commercial kit for the determination of glucose, to monitor an ethanolic fermentation was analyzed. The determination is based on the electrochemical oxidation reaction of NADH that [...] Read more.
The possibility of using an electrochemical biosensor, using screen-printed electrodes modified with a carbonaceous material and a commercial kit for the determination of glucose, to monitor an ethanolic fermentation was analyzed. The determination is based on the electrochemical oxidation reaction of NADH that occurs at a potential where the components of the kit do not generate a current signal, even in the presence of the fermentation medium. The electrochemical system was used to analyze the variation of glucose concentration during a laboratory-scale fermentation. The results were contrasted with the variation of standard characterization parameters such as pH, total soluble solids (TSS), the viability of the yeast, and concentration of ethanol produced. Of these values, the total soluble solids should be related to the concentration of glucose obtained by the electrochemical sensor, however, this last measure is more specific for sugar since the TSS refers to all soluble solids. The obtained results allow us to verify the usefulness of the electrochemical method for real-time monitoring of a fermentation. Full article
(This article belongs to the Special Issue Chemosensors and Biosensors for Food Quality and Safety)
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Open AccessArticle Long- and Short-Range Ordered Gold Nanoholes as Large-Area Optical Transducers in Sensing Applications
Chemosensors 2019, 7(1), 13; https://doi.org/10.3390/chemosensors7010013
Received: 14 February 2019 / Revised: 9 March 2019 / Accepted: 12 March 2019 / Published: 15 March 2019
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Abstract
Unconventional lithography (such as nanosphere lithography (NSL) and colloidal lithography (CL)) is an attractive alternative to sequential and very expensive conventional lithography for the low-cost fabrication of large-area nano-optical devices. Among these, nanohole (NH) arrays are widely studied in nanoplasmonics as transducers for [...] Read more.
Unconventional lithography (such as nanosphere lithography (NSL) and colloidal lithography (CL)) is an attractive alternative to sequential and very expensive conventional lithography for the low-cost fabrication of large-area nano-optical devices. Among these, nanohole (NH) arrays are widely studied in nanoplasmonics as transducers for sensing applications. In this work, both NSL and CL are implemented to fabricate two-dimensional distributions of gold NHs. In the case of NSL, highly ordered arrays of gold NHs distributed in a hexagonal lattice onto glass substrates were fabricated by a simple and reproducible approach based on the self-assembling of close-packed 500 nm diameter polystyrene particles at an air/water interface. After the transfer onto a solid substrate, the colloidal masks were processed to reduce the colloidal size in a controllable way. In parallel, CL was implemented with short-range ordered gold NH arrays onto glass substrates that were fabricated by electrostatically-driven self-assembly of negatively charged colloids onto a polydiallyldimethylammonium (PDDA) monolayer. These distributions were optimized as a function of the colloidal adsorption time. For both approaches, controllable and reproducible procedures are presented and discussed. The optical responses of the NH structures are related to the short-range ordering level, and their good performances as refractive index transducers are demonstrated. Full article
(This article belongs to the Special Issue Hierarchical Nanostructures for Gas Sensors)
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Open AccessArticle Porous Gig-Lox TiO2 Doped with N2 at Room Temperature for P-Type Response to Ethanol
Chemosensors 2019, 7(1), 12; https://doi.org/10.3390/chemosensors7010012
Received: 23 January 2019 / Revised: 28 February 2019 / Accepted: 5 March 2019 / Published: 12 March 2019
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Abstract
Nanostructured materials represent a breakthrough in many fields of application. Above all for sensing, the use of nanostructures with a high surface/volume ratio is strategic to raise the sensitivity towards dangerous environmental gas species. A new Dc-Reactive sputtering Deposition method has been applied [...] Read more.
Nanostructured materials represent a breakthrough in many fields of application. Above all for sensing, the use of nanostructures with a high surface/volume ratio is strategic to raise the sensitivity towards dangerous environmental gas species. A new Dc-Reactive sputtering Deposition method has been applied to grow highly porous p-type nitrogen-doped titanium oxide layers by modifying the previously developed reactive sputtering method called gig-lox. The doping of the films was achieved at room temperature by progressive incorporation of nitrogen species during the deposition process. Two different amounts of N2 were introduced into the deposition chamber at flow rates of 2 and 5 standard cubic centimeter per minutes (sccm) for doping. It has been found that the N2 uptake reduces the deposition rate of the TiO2 film whilst the porosity and the roughness of the grown layer are not penalized. Despite the low amount of N2, using 2 sccm of gas resulted in proper doping of the TiO2 film as revealed by XPS Analyses. In this case, nitrogen atoms are mainly arranged in substitutional positions with respect to the oxygen atoms inside the lattice, and this defines the p-type character of the growing layer. Above this strategic structural modification, the multibranched spongy porosity, peculiar of the gig-lox growth, is still maintained. As proof of concept of the achievements, a sensing device was prepared by combining this modified gig-lox deposition method with state-of-the-art hot-plate technology to monitor the electrical response to ethanol gas species. The sensor exhibited a sensitivity of a factor of ≈2 to 44 ppm of ethanol at ≈200 °C as measured by a rise in the layer resistivity according to the p-type character of the material. At the higher temperature of ≈350 °C, the sensor turned to n-type as without doping. This behavior was related to a loss of nitrogen content inside the film during the annealing. It was indeed proved that p-type doping of a gig-lox sponge during growth is feasible, even at room temperature, without losing the layer porosity and the capability to host and detect environmental species. Moreover, the material integration on a device is simply done as the last production step. Easy TiO2 doping procedures, combined with porosity, are of general purpose and interest for several applications even on flexible substrates. Full article
(This article belongs to the Special Issue Nanotechnology Efforts for Chemical Sensors)
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Open AccessArticle Sensors Based on Amino Group Surface-Modified CNTs
Chemosensors 2019, 7(1), 11; https://doi.org/10.3390/chemosensors7010011
Received: 21 January 2019 / Revised: 15 February 2019 / Accepted: 27 February 2019 / Published: 5 March 2019
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Abstract
This article discusses the possibility of the fabrication of a highly sensitive sensor based on single-walled carbon nanotubes surface modified with functional amino groups (-NH2). The sensor potential for detection of alkali (sodium, lithium, and potassium) metals was investigated. The results [...] Read more.
This article discusses the possibility of the fabrication of a highly sensitive sensor based on single-walled carbon nanotubes surface modified with functional amino groups (-NH2). The sensor potential for detection of alkali (sodium, lithium, and potassium) metals was investigated. The results of computer simulation of the interaction process between the sensor and an arbitrary surface of the modified tube containing atoms of the studied metals are presented. The calculations were carried out within the framework of the density functional theory (DFT) method using the molecular cluster model. It has been proved that surface-modified ammonium carbon nanotubes show high sensitivity for the metal atoms under study. Full article
(This article belongs to the Special Issue Carbon Nanotube Sensors)
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Open AccessFeature PaperReview Electrochemical Immuno- and Aptasensors for Mycotoxin Determination
Chemosensors 2019, 7(1), 10; https://doi.org/10.3390/chemosensors7010010
Received: 31 January 2019 / Revised: 24 February 2019 / Accepted: 26 February 2019 / Published: 4 March 2019
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Abstract
Modern analysis of food and feed is mostly focused on development of fast and reliable portable devices intended for field applications. In this review, electrochemical biosensors based on immunological reactions and aptamers are considered in the determination of mycotoxins as one of most [...] Read more.
Modern analysis of food and feed is mostly focused on development of fast and reliable portable devices intended for field applications. In this review, electrochemical biosensors based on immunological reactions and aptamers are considered in the determination of mycotoxins as one of most common contaminants able to negatively affect human health. The characteristics of biosensors are considered from the point of view of general principles of bioreceptor implementation and signal transduction providing sub-nanomolar detection limits of mycotoxins. Moreover, the modern trends of bioreceptor selection and modification are discussed as well as future trends of biosensor development for mycotoxin determination are considered. Full article
(This article belongs to the Special Issue Chemical Sensors for Heavy Metals/Toxin Detection)
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Open AccessReview Review on Nanomaterial-Based Melamine Detection
Received: 27 November 2018 / Revised: 14 February 2019 / Accepted: 15 February 2019 / Published: 20 February 2019
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Abstract
Illegal adulteration of milk products by melamine and its analogs has become a threat to the world. In 2008, the misuse of melamine with infant formula caused serious effects on babies of China. Thereafter, the government of China and the US Food and [...] Read more.
Illegal adulteration of milk products by melamine and its analogs has become a threat to the world. In 2008, the misuse of melamine with infant formula caused serious effects on babies of China. Thereafter, the government of China and the US Food and Drug Administration (FDA) limited the use of melamine of 1 mg/kg for infant formula and 2.5 mg/kg for other dairy products. Similarly, the World Health Organization (WHO) has also limited the daily intake of melamine of 0.2 mg/kg body weight per day. Many sensory schemes have been proposed by the scientists for carrying out screening on melamine poisoning. Among them, nanomaterial-based sensing techniques are very promising in terms of real-time applicability. These materials uncover and quantify the melamine by means of diverse mechanisms, such as fluorescence resonance energy transfer (FRET), aggregation, inner filter effect, surface-enhanced Raman scattering (SERS), and self-assembly, etc. Nanomaterials used for the melamine determination include carbon dots, quantum dots, nanocomposites, nanocrystals, nanoclusters, nanoparticles, nanorods, nanowires, and nanotubes. In this review, we summarize and comment on the melamine sensing abilities of these nanomaterials for their suitability and future research directions. Full article
(This article belongs to the Special Issue Nanomaterial Based Chemical Sensors)
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Open AccessArticle Inkjet Printed Interdigitated Biosensor for Easy and Rapid Detection of Bacteriophage Contamination: A Preliminary Study for Milk Processing Control Applications
Received: 29 November 2018 / Revised: 7 February 2019 / Accepted: 8 February 2019 / Published: 18 February 2019
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Abstract
Bacteriophages are responsible for significant material and time losses in the dairy industry. This because these viruses infect the selected lactic starter cultures used for milk fermentation, i.e., the first stage toward cheese production. Standard detection techniques are time- and labor-consuming, causing huge [...] Read more.
Bacteriophages are responsible for significant material and time losses in the dairy industry. This because these viruses infect the selected lactic starter cultures used for milk fermentation, i.e., the first stage toward cheese production. Standard detection techniques are time- and labor-consuming, causing huge costs related to production plant sanitation and product wasting. A new type of biosensor for early detection of bacteriophage contamination is highly demanded by the milk processing market, and inkjet-printed electrochemical sensors could be the answer. Inkjet printing is a well-known technology that has been revisited in recent years, using silver nanoparticle (AgNP) based inks for low-cost and easy fabrication of sensing and biosensing systems on flexible and eco-compatible substrates. In this research, we studied inkjet printing for the manufacturing of both interdigitated electrodes arrays (IDEAs), and a versatile system to monitor bacterial cultures by electrochemical impedance spectroscopy (EIS). In particular, we studied this biosensing system for the detection of bacteriophages by comparing its performance with standard microbiological methods. We performed electrical and morphological characterizations of the devices produced with a consumer-use inkjet printer with commercial AgNPs ink on flexible substrates, such as office paper, polyethylene (PET), and photo paper. We used light microscopy optical analysis, profilometry, atomic force microscopy (AFM), and scanning electron microscopy (SEM) imaging to define the objects resolution, their real dimensions, and thickness. We also investigated the devices’ conductivity and layout, by EIS measurements with a standard buffer solution, i.e., phosphate buffered saline (PBS). Finally, we tested our system by monitoring Lactococcus lactis cultures and bacteriophage infection. We compared the results to those obtained by two standard microbiological methods in terms of response time, proving that our technique requires less than half the time of other methods and no specialized personnel. Full article
(This article belongs to the Special Issue Thin Film Based Sensors)
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Open AccessArticle Deposition Time and Annealing Effects of ZnO Seed Layer on Enhancing Vertical Alignment of Piezoelectric ZnO Nanowires
Received: 29 December 2018 / Revised: 6 February 2019 / Accepted: 11 February 2019 / Published: 13 February 2019
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Abstract
Well aligned crystalline zinc oxide (ZnO) nanowires (NWs) on ZnO/Au/Ti/Si substrates were grown by so-called “hydrothermal synthesis”. ZnO seed layers with different thicknesses ranging from 5 to 100 nm, achieved by controlling the deposition time, were prepared by radio-frequency sputtering, followed by a [...] Read more.
Well aligned crystalline zinc oxide (ZnO) nanowires (NWs) on ZnO/Au/Ti/Si substrates were grown by so-called “hydrothermal synthesis”. ZnO seed layers with different thicknesses ranging from 5 to 100 nm, achieved by controlling the deposition time, were prepared by radio-frequency sputtering, followed by a post-annealing treatment in air at 400 °C. The effects of deposition time and annealing treatment of ZnO seed layers on the subsequent growth of ZnO NWs were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The experimental results reveal that the quality and growth behaviors of ZnO NWs are strongly dependent on both the thickness and the heat treatment of the ZnO seed layers. This work is an optimization step of an easy, cost-effective, and industrially scalable process flow recently developed for the fabrication of a high performance, nanocomposite-based stretchable nanogenerator (SNG) on polydimethylsiloxane (PDMS) substrate. The morphological improvement of hydrothermally grown ZnO NWs may therefore lead to higher performance SNGs for the targeted application of mechanical energy harvesting, in order to supply flexible and wearable electronics. Full article
(This article belongs to the Special Issue Nanotechnology Efforts for Chemical Sensors)
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Open AccessArticle Impedance Study of Dopamine Effects after Application on 2D and 3D Neuroblastoma Cell Cultures Developed on a 3D-Printed Well
Received: 30 November 2018 / Revised: 25 January 2019 / Accepted: 30 January 2019 / Published: 5 February 2019
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Abstract
In this work, the assessment of the interactions of a bioactive substance applied to immobilized cells in either a two-dimensional (2D) or three-dimensional (3D) arrangement mimicking in vivo tissue conditions is presented. In particular, dopamine (DA) was selected as a stimulant for the [...] Read more.
In this work, the assessment of the interactions of a bioactive substance applied to immobilized cells in either a two-dimensional (2D) or three-dimensional (3D) arrangement mimicking in vivo tissue conditions is presented. In particular, dopamine (DA) was selected as a stimulant for the implementation of an impedance analysis with a specific type of neural cells (murine neuroblastoma). The aim of this study was the extraction of calibration curves at various frequencies with different known dopamine concentrations for the description of the behavior of dopamine applied to 2D and 3D cell cultures. The results present the evaluation of the mean impedance value for each immobilization technique in each frequency. The differential responses showed the importance of the impedance when frequency is applied in both 2D and 3D immobilization cases. More specifically, in 2D immobilization matrix impedance shows higher values in comparison with the 3D cell culture. Additionally, in the 3D case, the impedance decreases with increasing concentration, while in the 2D case, an opposite behavior was observed. Full article
(This article belongs to the Special Issue Printed Electroanalytical Tools for De-Centralized Applications)
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Open AccessArticle Fluorescence-Based Detection of Benzene, Toluene, Ethylbenzene, Xylene, and Cumene (BTEXC) Compounds in Fuel-Contaminated Snow Environments
Received: 5 December 2018 / Revised: 3 January 2019 / Accepted: 10 January 2019 / Published: 15 January 2019
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Abstract
Reported herein is the sensitive and selective cyclodextrin-promoted fluorescence detection of benzene, toluene, ethylbenzene, xylene, and cumene (BTEXC) fuel components in contaminated snow samples collected from several locations in the state of Rhode Island. This detection method uses cyclodextrin as a supramolecular scaffold [...] Read more.
Reported herein is the sensitive and selective cyclodextrin-promoted fluorescence detection of benzene, toluene, ethylbenzene, xylene, and cumene (BTEXC) fuel components in contaminated snow samples collected from several locations in the state of Rhode Island. This detection method uses cyclodextrin as a supramolecular scaffold to promote analyte-specific, proximity-induced fluorescence modulation of a high-quantum-yield fluorophore, which leads to unique fluorescence responses for each cyclodextrin-analyte-fluorophore combination investigated and enables unique pattern identifiers for each analyte using linear discriminant analysis (LDA). This detection method operates with high levels of sensitivity (sub-micromolar detection limits), selectivity (100% differentiation between structurally similar compounds, such as ortho-, meta-, and para-xylene isomers), and broad applicability (for different snow samples with varying chemical composition, pH, and electrical conductivity). The high selectivity, sensitivity, and broad applicability of this method indicate significant potential in the development of practical detection devices for aromatic toxicants in complex environments. Full article
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Open AccessEditorial Acknowledgement to Reviewers of Chemosensors in 2018
Received: 8 January 2019 / Accepted: 8 January 2019 / Published: 8 January 2019
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Abstract
Rigorous peer-review is the corner-stone of high-quality academic publishing [...]
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Open AccessReview Thin Films Sensor Devices for Mycotoxins Detection in Foods: Applications and Challenges
Received: 28 November 2018 / Revised: 20 December 2018 / Accepted: 20 December 2018 / Published: 4 January 2019
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Abstract
Mycotoxins are a group of secondary metabolites produced by different species of filamentous fungi and pose serious threats to food safety due to their serious human and animal health impacts such as carcinogenic, teratogenic and hepatotoxic effects. Conventional methods for the detection of [...] Read more.
Mycotoxins are a group of secondary metabolites produced by different species of filamentous fungi and pose serious threats to food safety due to their serious human and animal health impacts such as carcinogenic, teratogenic and hepatotoxic effects. Conventional methods for the detection of mycotoxins include gas chromatography and high-performance liquid chromatography coupled with mass spectrometry or other detectors (fluorescence or UV detection), thin layer chromatography and enzyme-linked immunosorbent assay. These techniques are generally straightforward and yield reliable results; however, they are time-consuming, require extensive preparation steps, use large-scale instruments, and consume large amounts of hazardous chemical reagents. Rapid detection of mycotoxins is becoming an increasingly important challenge for the food industry in order to effectively enforce regulations and ensure the safety of food and feed. In this sense, several studies have been done with the aim of developing strategies to detect mycotoxins using sensing devices that have high sensitivity and specificity, fast analysis, low cost and portability. The latter include the use of microarray chips, multiplex lateral flow, Surface Plasmon Resonance, Surface Enhanced Raman Scattering and biosensors using nanoparticles. In this perspective, thin film sensors have recently emerged as a good candidate technique to meet such requirements. This review summarizes the application and challenges of thin film sensor devices for detection of mycotoxins in food matrices. Full article
(This article belongs to the Special Issue Thin Film Based Sensors)
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Open AccessArticle Real-Time Frequency Tracking of an Electro-Thermal Piezoresistive Cantilever Resonator with ZnO Nanorods for Chemical Sensing
Received: 29 October 2018 / Revised: 21 December 2018 / Accepted: 24 December 2018 / Published: 3 January 2019
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Abstract
The asymmetric resonance response in electro-thermal piezoresistive cantilever resonators causes a need of an optimization treatment for taking parasitic actuation-sensing effects into account. An electronic reference circuit for signal subtraction, integrated with the cantilever resonator has the capability to reduce the effect of [...] Read more.
The asymmetric resonance response in electro-thermal piezoresistive cantilever resonators causes a need of an optimization treatment for taking parasitic actuation-sensing effects into account. An electronic reference circuit for signal subtraction, integrated with the cantilever resonator has the capability to reduce the effect of parasitic coupling. Measurement results demonstrated that a symmetric amplitude shape (Lorentzian) and an optimized phase characteristic (i.e., monotonically decreasing) were successfully extracted from an asymmetric resonance response. With the monotonic phase response, real-time frequency tracking can be easier to implement using a phase-locked loop (PLL) system. In this work, an electro-thermal piezoresistive cantilever resonator functionalized with self-assembled monolayers of chitosan-covered ZnO nanorod arrays as sensitive layers has been investigated under different relative humidity (rH) levels. Enhancement of resonance phase response has been demonstrated by implementing the reference signal subtraction. Subsequently, a lock-in amplifier integrated with PLL system (MFLI, Zurich Instruments, Zurich, Switzerland) was then employed for continuously tracking the resonant frequency. As a result, we find a good correlation of frequency shift (∆f0) with change in rH monitored using a commercial reference sensor. Full article
(This article belongs to the Special Issue Nanotechnology Efforts for Chemical Sensors)
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Open AccessArticle Electrochemically Prepared Unzipped Single Walled Carbon Nanotubes-MnO2 Nanostructure Composites for Hydrogen Peroxide and Glucose Sensing
Received: 14 November 2018 / Revised: 21 December 2018 / Accepted: 24 December 2018 / Published: 3 January 2019
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Amperometric hydrogen peroxide (H2O2) and glucose biosensors based on unzipped carbon nanotubes with modified glassy carbon electrode (GCE) have been successfully fabricated via a facile electrochemical oxidative method. In this work, we investigated the feasibility of this new form [...] Read more.
Amperometric hydrogen peroxide (H2O2) and glucose biosensors based on unzipped carbon nanotubes with modified glassy carbon electrode (GCE) have been successfully fabricated via a facile electrochemical oxidative method. In this work, we investigated the feasibility of this new form of carbon nanomaterial as a substrate electrode material for fabricating sensitive platform for H2O2 and glucose sensors. For this purpose, the manganese oxide (MnO2)/unzipped single-walled carbon nanotubes (SWCNTs) film was synthesized by the cyclic voltammetry method. The developed sensing film, MnO2/unzipped SWCNTs/GCE, displayed a satisfactory analytical performance for H2O2, including a wide linear range of 2.0 × 10−6 to 5.0 × 10−3 M with a detection limit of 0.31 × 10−6 M (10.7 ppb). This film was further applied for glucose sensing with a linearity range of 0.01 to 1.2 mM with a correlation coefficient of 0.9822 in the physiological pH (7.4). This facile, fast, environmentally-friendly, and economical preparation strategy of carbon nanomaterial-based electrode materials opens up the possibility of developing high quality biocompatible hydrogen peroxide and glucose sensors. Full article
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