A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
Selected papers from the latest issue:
Fabrication of stable low voltage organic bistable memory device
13 November 2011, 00:07:42
Publication year: 2011
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Ch.V.V. Ramana, M.K. Moodely, V. Kannan, A. Maity, J. Jayaramudu, ...
Organic bistable memory device was fabricated by spin coating of polymethyl methacrylate (PMMA): ZnO nanoparticles onto ITO coated glass. The thin films were characterized by Raman, SEM, AFM and FTIR spectroscopies. The electrical characterization showed that the two-terminal device exhibited excellent switching characteristics with ON/OFF ratio greater than 2 × 10when the voltage was swept between -2 V and +2 V. The device maintained its state even after removal of the bias voltage. Device did not show degradation after 1-h retention test at 120 °C. The memory functionality was consistent even after multiple cycles of operation and the device is reproducible. The switching mechanism is discussed on the basis of carrier transport mechanism. This demonstration provides a class of memory devices with the potential for extremely low-cost, low-power consumption applications, such as digital memory cell.
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Ch.V.V. Ramana, M.K. Moodely, V. Kannan, A. Maity, J. Jayaramudu, ...
Organic bistable memory device was fabricated by spin coating of polymethyl methacrylate (PMMA): ZnO nanoparticles onto ITO coated glass. The thin films were characterized by Raman, SEM, AFM and FTIR spectroscopies. The electrical characterization showed that the two-terminal device exhibited excellent switching characteristics with ON/OFF ratio greater than 2 × 10when the voltage was swept between -2 V and +2 V. The device maintained its state even after removal of the bias voltage. Device did not show degradation after 1-h retention test at 120 °C. The memory functionality was consistent even after multiple cycles of operation and the device is reproducible. The switching mechanism is discussed on the basis of carrier transport mechanism. This demonstration provides a class of memory devices with the potential for extremely low-cost, low-power consumption applications, such as digital memory cell.
Highly Selective Amperometric Sensors for Carbon Monoxide Detection in Exhaust Gas
13 November 2011, 00:07:42
Publication year: 2011
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Chanadda Phawachalotorn, Oravan Sanguanruang, Tatsumi Ishihara
An amperometric electrochemical sensor based on LaGaO3was demonstrated as highly sensitive to carbon monoxide (CO) in the temperatures ranging from 300 °C to 500 °C. In the present study, various Fe-doped LaGaO3electrolytes (La0.8Sr0.2Ga0.8Mg0.2-xFexO3; x = 0.05, 0.10, 0.15, 0.2 and La0.8Sr0.2Ga1-xFexO3; x = 0.10, 0.15, 0.2, 0.3) coupled with Au10wt%-In1.9Sn0.1O3(ITO955) and RuO2-La0.6Sr0.4CoO3(LSC64) as the electrode catalysts were investigated. Highest sensitivity was achieved at 8.83 mA(decade (at 500 °C) by doping 15 mol% Fe into electrolyte (denoted as LSGF 828515) among the examined electrolytes. The sensitivities of all studied sensors were high and the current increased with increasing CO concentration. The sensors were fast, highly sensitive to CO and almost insensitive to other coexisting gases such as CH4, CO2, and H2. Therefore, this sensor can be used for CO monitoring of exhaust gas from a small indoor combustion source.
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Chanadda Phawachalotorn, Oravan Sanguanruang, Tatsumi Ishihara
An amperometric electrochemical sensor based on LaGaO3was demonstrated as highly sensitive to carbon monoxide (CO) in the temperatures ranging from 300 °C to 500 °C. In the present study, various Fe-doped LaGaO3electrolytes (La0.8Sr0.2Ga0.8Mg0.2-xFexO3; x = 0.05, 0.10, 0.15, 0.2 and La0.8Sr0.2Ga1-xFexO3; x = 0.10, 0.15, 0.2, 0.3) coupled with Au10wt%-In1.9Sn0.1O3(ITO955) and RuO2-La0.6Sr0.4CoO3(LSC64) as the electrode catalysts were investigated. Highest sensitivity was achieved at 8.83 mA(decade (at 500 °C) by doping 15 mol% Fe into electrolyte (denoted as LSGF 828515) among the examined electrolytes. The sensitivities of all studied sensors were high and the current increased with increasing CO concentration. The sensors were fast, highly sensitive to CO and almost insensitive to other coexisting gases such as CH4, CO2, and H2. Therefore, this sensor can be used for CO monitoring of exhaust gas from a small indoor combustion source.
Detection of bisphenol A using an opal photonic crystal sensor
13 November 2011, 00:07:42
Publication year: 2011
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Chun Guo, Caihong Zhou, Na Sai, BaoAn Ning, Ming Liu, ...
A new opal photonic crystal sensor (OPCS) that allows the detection of label-free bisphenol A (BPA) is proposed in the current study. The concept of developing photonic-based sensors using combined photonic crystal technology and molecular imprinting techniques is introduced. First batches of the BPA-imprinted monodisperse PMMA spheres with a diameter of 220( ( 5)nm were prepared based on the suspension polymerization, so numerous nanocavities derived from BPA imprinting were distributed in the PMMA spheres. The liquid monodisperse microspheres were made into a polymerized crystalline colloidal array (PCCA) opal photonic crystal sensor. The inherent high affinity of the nanocavities distributed in the sphere allows OPCS to recognize BPA specifically. The sensor is characterized by a 3D-ordered interconnected lattice structure. Between the monospheres, there are well-arranged pores allowing the target molecules to embed and transport. As a result, changes in diffraction intensity which are related to BPA concentrations can be observed with the sensor. The detection ranges of OPCS are at 1 ng/ml–1 μg/ml level. The new sensory system has high selectivity of the target molecules in their natural forms, is easy to use, and costs low. Overall, the proposed approach provides a versatile analytical system for the establishment of a new sensor for the detection of endocrine-disrupting chemicals.
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Chun Guo, Caihong Zhou, Na Sai, BaoAn Ning, Ming Liu, ...
A new opal photonic crystal sensor (OPCS) that allows the detection of label-free bisphenol A (BPA) is proposed in the current study. The concept of developing photonic-based sensors using combined photonic crystal technology and molecular imprinting techniques is introduced. First batches of the BPA-imprinted monodisperse PMMA spheres with a diameter of 220( ( 5)nm were prepared based on the suspension polymerization, so numerous nanocavities derived from BPA imprinting were distributed in the PMMA spheres. The liquid monodisperse microspheres were made into a polymerized crystalline colloidal array (PCCA) opal photonic crystal sensor. The inherent high affinity of the nanocavities distributed in the sphere allows OPCS to recognize BPA specifically. The sensor is characterized by a 3D-ordered interconnected lattice structure. Between the monospheres, there are well-arranged pores allowing the target molecules to embed and transport. As a result, changes in diffraction intensity which are related to BPA concentrations can be observed with the sensor. The detection ranges of OPCS are at 1 ng/ml–1 μg/ml level. The new sensory system has high selectivity of the target molecules in their natural forms, is easy to use, and costs low. Overall, the proposed approach provides a versatile analytical system for the establishment of a new sensor for the detection of endocrine-disrupting chemicals.
Gold Nanoparticles-Modified Screen-Printed Carbon Electrodes For Anodic Stripping Voltammetric Determination Of Mercury In Ambient Water Samples
13 November 2011, 00:07:42
Publication year: 2011
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
E. Bernalte, C. Marín Sánchez, E. Pinilla Gil
We present here a simple, fast and cheap procedure for the determination of Hg(II) by square wave anodic stripping voltammetry (SWASV) at a commercial gold nanoparticles-modified screen-printed carbon electrodes (AuNPs-SPCEs), as a tool for environmental waters monitoring. The advantages of electrode nanostructuration are exploited, e.g. no stirring for the deposition step is needed. The surface of the gold nanostructured screen-printed carbon electrodes were characterized using SEM, XPS and electrochemical methods. All experimental variables involved in the voltammetric stripping method were optimized to develop a reliable method capable of measuring dissolved mercury in the low ng/mL range. The proposed method was tested with the NIST 1641d Mercury in Water Standard Reference Material with good agreement. The applicability of the AuNPs-SPCEs for Hg(II) determination in real ambient water samples, namely rain water, river water and industrial waste water, without any sample pretreatment, was successfully demonstrated.
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
E. Bernalte, C. Marín Sánchez, E. Pinilla Gil
We present here a simple, fast and cheap procedure for the determination of Hg(II) by square wave anodic stripping voltammetry (SWASV) at a commercial gold nanoparticles-modified screen-printed carbon electrodes (AuNPs-SPCEs), as a tool for environmental waters monitoring. The advantages of electrode nanostructuration are exploited, e.g. no stirring for the deposition step is needed. The surface of the gold nanostructured screen-printed carbon electrodes were characterized using SEM, XPS and electrochemical methods. All experimental variables involved in the voltammetric stripping method were optimized to develop a reliable method capable of measuring dissolved mercury in the low ng/mL range. The proposed method was tested with the NIST 1641d Mercury in Water Standard Reference Material with good agreement. The applicability of the AuNPs-SPCEs for Hg(II) determination in real ambient water samples, namely rain water, river water and industrial waste water, without any sample pretreatment, was successfully demonstrated.
Simultaneous OWLS and EIS monitoring of supported lipid bilayers with the pore forming peptide melittin
13 November 2011, 00:07:42
Publication year: 2011
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Kaori Sugihara, Marco Delai, Istvan Szendro, Orane Guillaume-Genti, János Vörös, ...
A simultaneous optical waveguide lightmode spectroscopy (OWLS) and electrochemical impedance spectroscopy (EIS) measurement was carried out for the investigation of a supported lipid bilayer and its interactions with a pore-forming peptide, melittin. It was achieved only after the optimization of the ITO coating on the waveguide to increase the electrical sensitivity and the functionalization of the waveguide with a polyelectrolyte to form a lipid bilayer over the ITO surface. The combined system enabled monitoring of melittin pore activities in a wider range of melittin concentrations than either technique alone (1 μg/ml <Cmelittin < 200 μg/ml). Furthermore, it provided unique information that could not be obtained by the individual methods, such as a better identification of the melittin-pore formation and an insight about the correlation between the total pore area vs adsorbed amount of melittin.
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Kaori Sugihara, Marco Delai, Istvan Szendro, Orane Guillaume-Genti, János Vörös, ...
A simultaneous optical waveguide lightmode spectroscopy (OWLS) and electrochemical impedance spectroscopy (EIS) measurement was carried out for the investigation of a supported lipid bilayer and its interactions with a pore-forming peptide, melittin. It was achieved only after the optimization of the ITO coating on the waveguide to increase the electrical sensitivity and the functionalization of the waveguide with a polyelectrolyte to form a lipid bilayer over the ITO surface. The combined system enabled monitoring of melittin pore activities in a wider range of melittin concentrations than either technique alone (1 μg/ml <Cmelittin < 200 μg/ml). Furthermore, it provided unique information that could not be obtained by the individual methods, such as a better identification of the melittin-pore formation and an insight about the correlation between the total pore area vs adsorbed amount of melittin.
Detection of Low Molecular Weight Compounds using Carbon Nanotube Grafted Resonators
13 November 2011, 00:07:42
Publication year: 2011
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Al. Palaniappan, W.H. Goh, U.H. Yildiz, B. Swarnalatha, S. Priyanka, ...
A biosensor platform based on single walled carbon nanotube (SWCNT) grafted quartz resonator is reported in this study. The generated SWCNT network on the resonator electrode is used to enhance the surface area for receptor immobilization and thereby the sensitivity. This approach enables detection of low molecular weight compounds in a direct assay format. Micro-gravimetric detection of two potentially harmful herbicides, atrazine and 2,4-dichlorophenoxyacetic acid (2,4-D) demonstrates the enhanced sensing capabilities of the developed biosensor platform. Antibodies raised against the herbicides are covalently attached to the SWCNTs, which are tethered on to the resonator electrodes via cysteine linkers. Imaging surface plasmon resonance and polarization modulation infrared reflection absorption spectroscopy are used to characterize the sensing surface and the covalent immobilization of the antibodies. The experimental results reveal that grafting SWCNT on resonator electrodes improve the sensing performance, as compared to a planar architecture, thereby enabling direct detection of atrazine and 2,4-D at analytically relevant concentration levels.
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
Al. Palaniappan, W.H. Goh, U.H. Yildiz, B. Swarnalatha, S. Priyanka, ...
A biosensor platform based on single walled carbon nanotube (SWCNT) grafted quartz resonator is reported in this study. The generated SWCNT network on the resonator electrode is used to enhance the surface area for receptor immobilization and thereby the sensitivity. This approach enables detection of low molecular weight compounds in a direct assay format. Micro-gravimetric detection of two potentially harmful herbicides, atrazine and 2,4-dichlorophenoxyacetic acid (2,4-D) demonstrates the enhanced sensing capabilities of the developed biosensor platform. Antibodies raised against the herbicides are covalently attached to the SWCNTs, which are tethered on to the resonator electrodes via cysteine linkers. Imaging surface plasmon resonance and polarization modulation infrared reflection absorption spectroscopy are used to characterize the sensing surface and the covalent immobilization of the antibodies. The experimental results reveal that grafting SWCNT on resonator electrodes improve the sensing performance, as compared to a planar architecture, thereby enabling direct detection of atrazine and 2,4-D at analytically relevant concentration levels.
CO optical sensing properties of nanocrystalline ZnO-Au films: effect of doping with transition metal ions
13 November 2011, 00:07:42
Publication year: 2011
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
E. Della Gaspera, M. Guglielmi, G. Perotto, S. Agnoli, G. Granozzi, ...
Zinc oxide nanocrystals, pure and doped with transition metal ions, have been synthesized using colloidal techniques; after purification and concentration protocols, the ZnO solutions are mixed with monodisperse Au colloidal suspensions and used for thin film depositions. The effect of the dopant ions on the structural, morphological and optical properties of the as-synthesized colloids as well as the nanocomposite thin films has been analyzed and discussed. The dopant presence has been found to affect the CO optical sensing properties of the nanocomposite ZnO-Au films: compared to pure ZnO, an increase in sensitivity up to 80% and 55% has been detected for Co-doped and Mn-doped ZnO respectively, while Ni-doped ZnO films show only minor improvements. This observation has been ascribed to the multiple oxidation states of cobalt and manganese ions that can facilitate electron transfer between the target gas and the semiconductive oxide matrix, and also to the lower surface concentration of Ni ions inside ZnO crystals, as compared to Co and Mn. A fast and reversible response after repeated CO exposures has been detected for all tested samples, and a linear response intensity with the order of magnitude of CO concentration has been observed in the 10-10000 ppm range, with a lower detection limit of 1-2 ppm.
Source: Sensors and Actuators B: Chemical, Available online 12 November 2011
E. Della Gaspera, M. Guglielmi, G. Perotto, S. Agnoli, G. Granozzi, ...
Zinc oxide nanocrystals, pure and doped with transition metal ions, have been synthesized using colloidal techniques; after purification and concentration protocols, the ZnO solutions are mixed with monodisperse Au colloidal suspensions and used for thin film depositions. The effect of the dopant ions on the structural, morphological and optical properties of the as-synthesized colloids as well as the nanocomposite thin films has been analyzed and discussed. The dopant presence has been found to affect the CO optical sensing properties of the nanocomposite ZnO-Au films: compared to pure ZnO, an increase in sensitivity up to 80% and 55% has been detected for Co-doped and Mn-doped ZnO respectively, while Ni-doped ZnO films show only minor improvements. This observation has been ascribed to the multiple oxidation states of cobalt and manganese ions that can facilitate electron transfer between the target gas and the semiconductive oxide matrix, and also to the lower surface concentration of Ni ions inside ZnO crystals, as compared to Co and Mn. A fast and reversible response after repeated CO exposures has been detected for all tested samples, and a linear response intensity with the order of magnitude of CO concentration has been observed in the 10-10000 ppm range, with a lower detection limit of 1-2 ppm.
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