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:
Boron δ-doped (111) diamond Solution Gate Field Effect Transistors
08 January 2012, 21:47:32
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 8 January 2012
Robert Edgington, A. Rahim Ruslinda, Syunsuke Sato, Yuichiro Ishiyama, Kyosuke Tsuge, ...
A solution gate field effect transistor (SGFET) using an oxidised boron δ-doped channel on (111) diamond is presented for the first time. Employing an optimised plasma chemical vapour deposition (PECVD) recipe to deposit δ-layers, SGFETs show improved current-voltage (I-V) characteristics in comparison to previous similar devices fabricated on (100) and polycrystalline diamond, where the device is shown to operate in the enhancement mode of operation, achieving channel pinch-off and drain-source current saturation within the electrochemical window of diamond. A maximum gain and transconductance of 3 and 200 μS/mm are extracted, showing comparable figures of merit to hydrogen-based SGFET. The oxidised device shows a site-binding model pH sensitivity of 36 mV/pH, displaying fast temporal responses. Considering the biocompatibility of diamond towards cells, the device's highly mutable transistor characteristics, pH sensitivity and stability against anodic oxidation common to hydrogen terminated diamond SGFET, oxidised boron δ-doped diamond SGFETs show promise for the recording of action potentials from electrogenic cells.
Source: Biosensors and Bioelectronics, Available online 8 January 2012
Robert Edgington, A. Rahim Ruslinda, Syunsuke Sato, Yuichiro Ishiyama, Kyosuke Tsuge, ...
A solution gate field effect transistor (SGFET) using an oxidised boron δ-doped channel on (111) diamond is presented for the first time. Employing an optimised plasma chemical vapour deposition (PECVD) recipe to deposit δ-layers, SGFETs show improved current-voltage (I-V) characteristics in comparison to previous similar devices fabricated on (100) and polycrystalline diamond, where the device is shown to operate in the enhancement mode of operation, achieving channel pinch-off and drain-source current saturation within the electrochemical window of diamond. A maximum gain and transconductance of 3 and 200 μS/mm are extracted, showing comparable figures of merit to hydrogen-based SGFET. The oxidised device shows a site-binding model pH sensitivity of 36 mV/pH, displaying fast temporal responses. Considering the biocompatibility of diamond towards cells, the device's highly mutable transistor characteristics, pH sensitivity and stability against anodic oxidation common to hydrogen terminated diamond SGFET, oxidised boron δ-doped diamond SGFETs show promise for the recording of action potentials from electrogenic cells.
Highlights
► Solution gate-FET using a boron δ-doped channel on (111) diamond was fabricated ► Enhancement mode operation with channel pinch-off and drain-source current saturation ► Maximum gain and transconductance of 3 and 200 μS/mm were achieved ► Showed a pH sensitivity of 36 mV/pH, displaying fast temporal responses ► Demonstrated stability against anodic oxidationUltrasensitive Electrochemical Immunosensor based on Au nanoparticals dotted carbon nanotube-graphene composite and functionalized mesoporous materials
07 January 2012, 01:50:17
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Juanjuan Lu, Shiquan Liu, Shenguang Ge, Mei Yan, Jinghua Yu, ...
A facile and sensitive electrochemical immunosensor for detection of human chorionic gonadotrophin (hCG) was designed by using functionalized mesoporous nanoparticles as bionanolabels. To construct high-performance electrochemical immunosensor, Au nanoparticles (AuNPs) dotted carbon nanotubes(MWCNTs)-graphene composite was immobilized on the working electrode, which can increase the surface area to capture a large amount of primary antibodies (Ab1) as well as improve the electronic transmission rate. The as-prepared bionanolabels. composed of mesoporous silica nanoparticles (MCM-41) coated with AuNPs through thionine linking, showed good adsorption of horseradish peroxidase-labeled secondary anti-hCG antibody. Interlayer thionine was not only a bridging agent between MCM-41 and AuNPs but also a excellent electron mediator. The approach provided a good linear response range from 0.005 to 500 mIU·mLwith a low detection limit of 0.0026 mIU·mL. The immunosensor showed good precision, acceptable stability and reproducibility. Satisfactory results were obtained for determination of hCG in human serum samples. The proposed method provides a new promising platform of clinical immunoassay for other biomolecules.
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Juanjuan Lu, Shiquan Liu, Shenguang Ge, Mei Yan, Jinghua Yu, ...
A facile and sensitive electrochemical immunosensor for detection of human chorionic gonadotrophin (hCG) was designed by using functionalized mesoporous nanoparticles as bionanolabels. To construct high-performance electrochemical immunosensor, Au nanoparticles (AuNPs) dotted carbon nanotubes(MWCNTs)-graphene composite was immobilized on the working electrode, which can increase the surface area to capture a large amount of primary antibodies (Ab1) as well as improve the electronic transmission rate. The as-prepared bionanolabels. composed of mesoporous silica nanoparticles (MCM-41) coated with AuNPs through thionine linking, showed good adsorption of horseradish peroxidase-labeled secondary anti-hCG antibody. Interlayer thionine was not only a bridging agent between MCM-41 and AuNPs but also a excellent electron mediator. The approach provided a good linear response range from 0.005 to 500 mIU·mLwith a low detection limit of 0.0026 mIU·mL. The immunosensor showed good precision, acceptable stability and reproducibility. Satisfactory results were obtained for determination of hCG in human serum samples. The proposed method provides a new promising platform of clinical immunoassay for other biomolecules.
Immobilization of Enzyme on Long Period Grating Fibers for Sensitive Glucose Detection
07 January 2012, 01:50:17
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Akash Deep, UmeshTiwari, Parveen Kumar, Vandana Mishra, SubhashC Jain, ...
Glucose oxidase (GOD) immobilized long period grating (LPG) fibershave beenproposed for thespecific and sensitivedetection of glucose. The treatment of LPG fibers with aminopropyltriethoxysilanehasinduced biding sites for the subsequent GOD immobilization.Field emission scanning electron microscopy, confocal laser scanning microscopy, infrared spectroscopy and Raman spectroscopy have provided detailed evidences about the effectiveness of the adopted biofunctionalization methodology. The enzyme activity is conserved during the immobilization step. Fabricated LPG sensor was tested on different glucose solutions to record the transmission spectra on an optical spectrum analyzer. The wavelength shifts in the transmission spectra are linearly correlated with the glucose concentration in the range 10–300 mg dL. The fabricated sensor gives fast response and is demonstrated to be of practical utility by determining glucose contents in blood samples. Proposed technique can further be extended to develop LPG fiber based novel,sensitive and label free nanosensors for disease diagnosis and clinical analysis
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Akash Deep, UmeshTiwari, Parveen Kumar, Vandana Mishra, SubhashC Jain, ...
Glucose oxidase (GOD) immobilized long period grating (LPG) fibershave beenproposed for thespecific and sensitivedetection of glucose. The treatment of LPG fibers with aminopropyltriethoxysilanehasinduced biding sites for the subsequent GOD immobilization.Field emission scanning electron microscopy, confocal laser scanning microscopy, infrared spectroscopy and Raman spectroscopy have provided detailed evidences about the effectiveness of the adopted biofunctionalization methodology. The enzyme activity is conserved during the immobilization step. Fabricated LPG sensor was tested on different glucose solutions to record the transmission spectra on an optical spectrum analyzer. The wavelength shifts in the transmission spectra are linearly correlated with the glucose concentration in the range 10–300 mg dL. The fabricated sensor gives fast response and is demonstrated to be of practical utility by determining glucose contents in blood samples. Proposed technique can further be extended to develop LPG fiber based novel,sensitive and label free nanosensors for disease diagnosis and clinical analysis
Highlights
► Glucose oxidase (GOD) has been covalently immobilized on the Long Period Grating (LPG) fiber surface to construct a sensitive glucose sensor ► Detailed investigations by FTIR spectrometry, Raman spectrometry, FESEM and Confocal Laser Scanning microscopy have confirmed the successful enzyme immobilization ► Constructed GOD immobilized LPG sensor is responsive to physiologically important glucose concentrations. Various important sensor optimizations parameters have been establishedMolecular imprinted nanoelectrodes for ultra sensitive detection of ovarian cancer marker
07 January 2012, 01:50:17
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Subramanian Viswanathan, Chinnakkaruppanan Rani, Susana Ribeiro, Cristina Delerue-Matos
The relentless discovery of cancer biomarkers demands improved methods for their detection. In this work, we developed protein imprinted polymer on three-dimensional gold nanoelectrode ensemble (GNEE) to detect epithelial ovarian cancer antigen-125 (CA 125), a protein biomarker associated with ovarian cancer. CA 125 is the standard tumor marker used to follow women during or after treatment for epithelial ovarian cancer. The template protein CA 125 was initially incorporated into the thin-film coating and, upon extraction of protein from the accessible surfaces on the thin film, imprints for CA125 were formed. The fabrication and analysis of the CA 125 imprinted GNEE was done by using cyclic voltammetry (CV), Differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. The surfaces of the very thin, protein imprinted sites on GNEE are utilized for immunospecific capture of CA 125 molecules, and the mass of bound on the electrode surface can be detected as a reduction in the faradic current from the redox marker. Under optimal conditions, the developed sensor showed good increments at the studied concentration range of 0.5-400 UmL. The lowest detection limit was found to be 0.5 U mL. Spiked human blood serum and unknown real serum samples were analyzed. The presence of non-specific proteins in the serum did not significantly affect the sensitivity of our assay. Molecular imprinting using synthetic polymers and nanomaterials provides an alternative approach to the trace detection of biomarker proteins.
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Subramanian Viswanathan, Chinnakkaruppanan Rani, Susana Ribeiro, Cristina Delerue-Matos
The relentless discovery of cancer biomarkers demands improved methods for their detection. In this work, we developed protein imprinted polymer on three-dimensional gold nanoelectrode ensemble (GNEE) to detect epithelial ovarian cancer antigen-125 (CA 125), a protein biomarker associated with ovarian cancer. CA 125 is the standard tumor marker used to follow women during or after treatment for epithelial ovarian cancer. The template protein CA 125 was initially incorporated into the thin-film coating and, upon extraction of protein from the accessible surfaces on the thin film, imprints for CA125 were formed. The fabrication and analysis of the CA 125 imprinted GNEE was done by using cyclic voltammetry (CV), Differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. The surfaces of the very thin, protein imprinted sites on GNEE are utilized for immunospecific capture of CA 125 molecules, and the mass of bound on the electrode surface can be detected as a reduction in the faradic current from the redox marker. Under optimal conditions, the developed sensor showed good increments at the studied concentration range of 0.5-400 UmL. The lowest detection limit was found to be 0.5 U mL. Spiked human blood serum and unknown real serum samples were analyzed. The presence of non-specific proteins in the serum did not significantly affect the sensitivity of our assay. Molecular imprinting using synthetic polymers and nanomaterials provides an alternative approach to the trace detection of biomarker proteins.
Highlights
► Imprinted polymer on gold nanoelectrode to detect ovarian cancer antigen-125 was developed. ► This sensor showed good increments at the concentration range of 0.5-400 UmL. ► MIPGNEE offers an alternative approach for the trace detection of CA125 biomarkers in clinical analysis.Simultaneous and rapid detection of six different mycotoxins using an immunochip
07 January 2012, 01:50:17
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Ying Wang, Nan Liu, Baoan Ning, Ming Liu, Junwen Li, ...
Mycotoxins are highly toxic contaminants in food, animal feed, and commodities. The study has developed an immunochip for quantifying the concentrations of six mycotoxins: aflatoxin B1, aflatoxin M1, deoxynivalenol, ochratoxin A, T-2 toxin, and zearalenone, which were added to drinking water. The complete antigens (Ags) of the mycotoxins were printed contactly and immobilized onto agarose-modified glass slides with 12 physically isolated subarrays, based on the reaction of both diffusion and covalent bond. The optimal concentration of each antigen and antibody (Ab) was obtained using an Ag–Ab immunoassay. Based on the indirect competitive immunoassay for the simultaneous detection of six mycotoxins in one single chip, six standard curves with good logistic correlation (R> 0.97) were respectively plotted. The working ranges (0.04–1.69, 0.45–3.90, 20.20–69.23, 35.68–363.18, 0.11–1.81, and 0.08–7.47 ng/mL, respectively) were calculated, as well as the median inhibitory concentrations (0.31 ± 0.04, 1.49 ± 0.21, 34.54 ± 1.30, 134.06 ± 11.75, 0.49 ± 0.05, and 1.54 ± 0.22 ng/mL, respectively), when six mycotoxins were detected simultaneously. Finally, the recovery rates in drinking water generally ranged from 80% to 120% on the same chip, with an intra-assay coefficient of variation lower than 15%. We successfully established an immunochip for simultaneous detection of six mycotoxins within 4 hours, with advantages of using minimal samples and being visually semiquantitative with our naked eyes. In summary, the method could be developed on one single chip for detecting multiple contaminants in actual samples.
Source: Biosensors and Bioelectronics, Available online 5 January 2012
Ying Wang, Nan Liu, Baoan Ning, Ming Liu, Junwen Li, ...
Mycotoxins are highly toxic contaminants in food, animal feed, and commodities. The study has developed an immunochip for quantifying the concentrations of six mycotoxins: aflatoxin B1, aflatoxin M1, deoxynivalenol, ochratoxin A, T-2 toxin, and zearalenone, which were added to drinking water. The complete antigens (Ags) of the mycotoxins were printed contactly and immobilized onto agarose-modified glass slides with 12 physically isolated subarrays, based on the reaction of both diffusion and covalent bond. The optimal concentration of each antigen and antibody (Ab) was obtained using an Ag–Ab immunoassay. Based on the indirect competitive immunoassay for the simultaneous detection of six mycotoxins in one single chip, six standard curves with good logistic correlation (R> 0.97) were respectively plotted. The working ranges (0.04–1.69, 0.45–3.90, 20.20–69.23, 35.68–363.18, 0.11–1.81, and 0.08–7.47 ng/mL, respectively) were calculated, as well as the median inhibitory concentrations (0.31 ± 0.04, 1.49 ± 0.21, 34.54 ± 1.30, 134.06 ± 11.75, 0.49 ± 0.05, and 1.54 ± 0.22 ng/mL, respectively), when six mycotoxins were detected simultaneously. Finally, the recovery rates in drinking water generally ranged from 80% to 120% on the same chip, with an intra-assay coefficient of variation lower than 15%. We successfully established an immunochip for simultaneous detection of six mycotoxins within 4 hours, with advantages of using minimal samples and being visually semiquantitative with our naked eyes. In summary, the method could be developed on one single chip for detecting multiple contaminants in actual samples.
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