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:An electrochemical aptasensor based on enzyme linked aptamer assay
30 October 2011, 20:44:33
Publication year: 2011
Source: Biosensors and Bioelectronics, Available online 29 October 2011
De-Wen Zhang, Cui-Jin Sun, Fang-Ting Zhang, Li Xu, Ying-Lin Zhou, ...
An aptamer is an artificial functional oligonucleic acid, which can interact with its target molecule with high affinity and specificity. Enzyme linked aptamer assay (ELAA) is developed to detect cocaine using aptamer fragment/cocaine configuration based on the affinity interaction between aptamer fragments with cocaine. The aptasensor was constructed by cleaving anticocaine aptamer into two fragments: one was assembled on a gold electrode surface, while the other was modified with biotin at 3′-end, which could be further labelled with streptavidin-horseradish peroxidase (SA-HRP). Upon binding with cocaine, the HRP-labelled aptamer fragment/cocaine complex formed on the electrode would increase the reduction current of hydroquinone (HQ) in the presence of H2O2. The sensitivity and the specificity of the proposed electrochemical aptasensor were investigated by differential pulse voltammetry (DPV). The results indicated that the DPV signal change could be used to sensitively detect cocaine with the dynamic range from 0.1 μM to 50 μM and the detection limit down to 20 nM (S/N = 3). The proposed aptasensor has the advantages of high sensitivity and low background current. Furthermore, a new configuration for ELAA requiring only a single aptamer sequence is constructed, which can be generalized for detecting different kinds of targets by cleaving the aptamers into two suitable segments.
Source: Biosensors and Bioelectronics, Available online 29 October 2011
De-Wen Zhang, Cui-Jin Sun, Fang-Ting Zhang, Li Xu, Ying-Lin Zhou, ...
An aptamer is an artificial functional oligonucleic acid, which can interact with its target molecule with high affinity and specificity. Enzyme linked aptamer assay (ELAA) is developed to detect cocaine using aptamer fragment/cocaine configuration based on the affinity interaction between aptamer fragments with cocaine. The aptasensor was constructed by cleaving anticocaine aptamer into two fragments: one was assembled on a gold electrode surface, while the other was modified with biotin at 3′-end, which could be further labelled with streptavidin-horseradish peroxidase (SA-HRP). Upon binding with cocaine, the HRP-labelled aptamer fragment/cocaine complex formed on the electrode would increase the reduction current of hydroquinone (HQ) in the presence of H2O2. The sensitivity and the specificity of the proposed electrochemical aptasensor were investigated by differential pulse voltammetry (DPV). The results indicated that the DPV signal change could be used to sensitively detect cocaine with the dynamic range from 0.1 μM to 50 μM and the detection limit down to 20 nM (S/N = 3). The proposed aptasensor has the advantages of high sensitivity and low background current. Furthermore, a new configuration for ELAA requiring only a single aptamer sequence is constructed, which can be generalized for detecting different kinds of targets by cleaving the aptamers into two suitable segments.
Highlights
► A simple and sensitive aptasensor for cocaine detection based on enzyme linked aptamer assay (ELAA) using aptamer fragment/target/aptamer fragment configuration is developed. ► The detection limit down to 20 nM for cocaine has been achieved by the reaction of H2O2and HQ catalyzed by HRP. ► The aptasensor shows the potential application in biological fluid. ► A new configuration for ELAA requiring only a single aptamer sequence can be generalized for detecting different kinds of targets.Antigen-specific T cell phenotyping microarrays using Grating Coupled Surface Plasmon Resonance Imaging and Surface Plasmon Coupled Emission
29 October 2011, 20:44:27
Publication year: 2011
Source: Biosensors and Bioelectronics, Available online 29 October 2011
James M. Rice, Lawrence J. Stern, Ernest F. Guignon, David A. Lawrence, Michael A. Lynes
The circulating population of peripheral T lymphocytes obtained from a blood sample can provide a large amount of information about an individual's medical status and history. Recent evidence indicates that the detection and functional characterization of antigen-specific T cell subsets within the circulating population may provide a diagnostic indicator of disease and has the potential to predict an individual's response to therapy. In this report, a microarray detection platform that combines grating-coupled surface plasmon resonance imaging (GCSPRI) and grating-coupled surface plasmon coupled emission (SPCE) fluorescence detection modalities was used to detect and characterize CD4T cells. The microspot regions of interest (ROIs) printed on the array consisted of immobilized antibodies or peptide loaded MHC monomers (p/MHC) as T cell capture ligands mixed with additional antibodies as cytokine capture ligands covalently bound to the surface of a corrugated gold sensor chip. Using optimized parameters, an unlabelled influenza peptide reactive T cell clone could be detected at a frequency of 0.1% in a mixed T cell sample using GCSPRI. Additionally, after cell binding was quantified, differential TH1 cytokine secretion patterns from a T cell clone cultured under TH1 or TH2 inducing conditions was detected using an SPCE fluorescence based assay. Differences in the secretion patterns of 3 cytokines, characteristic of the inducing conditions, indicated that differences were a consequence of the functional status of the captured cells. A dual mode GCSPRI/SPCE assay can provide a rapid, high content T cell screening/characterization tool that is useful for diagnosing disease, evaluating vaccination efficacy, or assessing responses to immunotherapeutics.
Source: Biosensors and Bioelectronics, Available online 29 October 2011
James M. Rice, Lawrence J. Stern, Ernest F. Guignon, David A. Lawrence, Michael A. Lynes
The circulating population of peripheral T lymphocytes obtained from a blood sample can provide a large amount of information about an individual's medical status and history. Recent evidence indicates that the detection and functional characterization of antigen-specific T cell subsets within the circulating population may provide a diagnostic indicator of disease and has the potential to predict an individual's response to therapy. In this report, a microarray detection platform that combines grating-coupled surface plasmon resonance imaging (GCSPRI) and grating-coupled surface plasmon coupled emission (SPCE) fluorescence detection modalities was used to detect and characterize CD4T cells. The microspot regions of interest (ROIs) printed on the array consisted of immobilized antibodies or peptide loaded MHC monomers (p/MHC) as T cell capture ligands mixed with additional antibodies as cytokine capture ligands covalently bound to the surface of a corrugated gold sensor chip. Using optimized parameters, an unlabelled influenza peptide reactive T cell clone could be detected at a frequency of 0.1% in a mixed T cell sample using GCSPRI. Additionally, after cell binding was quantified, differential TH1 cytokine secretion patterns from a T cell clone cultured under TH1 or TH2 inducing conditions was detected using an SPCE fluorescence based assay. Differences in the secretion patterns of 3 cytokines, characteristic of the inducing conditions, indicated that differences were a consequence of the functional status of the captured cells. A dual mode GCSPRI/SPCE assay can provide a rapid, high content T cell screening/characterization tool that is useful for diagnosing disease, evaluating vaccination efficacy, or assessing responses to immunotherapeutics.
Ultrasensitive and dual functional colorimetric sensors for mercury (II) ions and hydrogen peroxide based on catalytic reduction property of silver nanoparticles
28 October 2011, 20:46:12
Publication year: 2011
Source: Biosensors and Bioelectronics, Available online 28 October 2011
Guang-Li Wang, Xiao-Ying Zhu, Huan-Jun Jiao, Yu-Ming Dong, Zai-Jun Li
The method provides an innovative dual functional sensors for mercury (II) ions and hydrogen peroxide. The addition of H2O2to the mixture of silver nanoparticles (AgNPs) and Hginduced color changes of the solution within several seconds even at 2.0 nM Hg. Other metallic ions could not induce color change even at 10 μM. Of importance, this probe was not only successfully applied to detect Hg, but also it could be used to sense H2O2at a concentration as low as 50 nM (by naked-eye). The outstanding sensitivity and selectivity property for Hgand H2O2resulted from the AgNPs mediated redcution of Hgto elementary Hg in the presence of H2O2, causing the aggregation and colorimetric response of AgNPs. This sensitive and selective colorimetric assay opens up a fresh insight of development facile and fast detection methods for metal ions and biomolecules using the special catalytic reactivity of AgNPs.
Source: Biosensors and Bioelectronics, Available online 28 October 2011
Guang-Li Wang, Xiao-Ying Zhu, Huan-Jun Jiao, Yu-Ming Dong, Zai-Jun Li
The method provides an innovative dual functional sensors for mercury (II) ions and hydrogen peroxide. The addition of H2O2to the mixture of silver nanoparticles (AgNPs) and Hginduced color changes of the solution within several seconds even at 2.0 nM Hg. Other metallic ions could not induce color change even at 10 μM. Of importance, this probe was not only successfully applied to detect Hg, but also it could be used to sense H2O2at a concentration as low as 50 nM (by naked-eye). The outstanding sensitivity and selectivity property for Hgand H2O2resulted from the AgNPs mediated redcution of Hgto elementary Hg in the presence of H2O2, causing the aggregation and colorimetric response of AgNPs. This sensitive and selective colorimetric assay opens up a fresh insight of development facile and fast detection methods for metal ions and biomolecules using the special catalytic reactivity of AgNPs.
Highlights
► Dual functional colorimetric sensors for mercury (II) ions and hydrogen peroxide. ► Hgwas reduced to elementary Hg by silver nanoparticles in the presence of H2O2. ► This method had ultra-high sensitivity and good selectivityLayer-by-layer self-assembly and electrochemistry: Applications in biosensing and bioelectronics
28 October 2011, 20:46:12
Publication year: 2011
Source: Biosensors and Bioelectronics, Available online 28 October 2011
Rodrigo M. Iost, Frank N. Crespilho
This paper provides an overview of different nanostructured architectures utilised in electrochemical devices and their application in biosensing and bioelectronics. Emphasis is placed on the fabrication of nanostructured films based on a layer-by-layer (LBL) films approach. We discuss the theory and the mechanism of charge transfer in polyelectrolyte multilayer films (PEM), as well as between biomolecules and redox centres, for the development of more sensitive and selective biosensors. Further, this paper presents an overview of topics involving the interaction between nanostructured materials, including metallic nanoparticles and carbon materials, and their effects on the preservation of the activity of biological molecules immobilised on electrode surfaces. This paper also presents examples of biological molecules utilised in film fabrication, such as DNA, several kinds of proteins, and oligonucleotides, and of the role of molecular interaction in biosensing performance. Towards the utilisation of LBL films, examples of several architectures and different electrochemical approaches demonstrate the potential of nanostructured LBL films for several applications that include the diagnosis and monitoring of diseases. Our main aim in this review is to survey what can assist researchers by presenting various approaches currently used in the field of bioelectrochemistry utilising supramolecular architectures based on an LBL approach for application in electrochemical biosensing.
Source: Biosensors and Bioelectronics, Available online 28 October 2011
Rodrigo M. Iost, Frank N. Crespilho
This paper provides an overview of different nanostructured architectures utilised in electrochemical devices and their application in biosensing and bioelectronics. Emphasis is placed on the fabrication of nanostructured films based on a layer-by-layer (LBL) films approach. We discuss the theory and the mechanism of charge transfer in polyelectrolyte multilayer films (PEM), as well as between biomolecules and redox centres, for the development of more sensitive and selective biosensors. Further, this paper presents an overview of topics involving the interaction between nanostructured materials, including metallic nanoparticles and carbon materials, and their effects on the preservation of the activity of biological molecules immobilised on electrode surfaces. This paper also presents examples of biological molecules utilised in film fabrication, such as DNA, several kinds of proteins, and oligonucleotides, and of the role of molecular interaction in biosensing performance. Towards the utilisation of LBL films, examples of several architectures and different electrochemical approaches demonstrate the potential of nanostructured LBL films for several applications that include the diagnosis and monitoring of diseases. Our main aim in this review is to survey what can assist researchers by presenting various approaches currently used in the field of bioelectrochemistry utilising supramolecular architectures based on an LBL approach for application in electrochemical biosensing.
Highlights
► This paper provides an overview of different nanostructured architectures utilised in biosensing and bioelectronics ► We discuss the theory and the mechanism of charge transfer in polyelectrolyte multilayer films ► Examples of several architectures and different electrochemical approaches demonstrate the potential of nanostructured LBL films ► We presents examples of biological molecules utilised in film fabrication, such as DNA, several kinds of proteins, and oligonucleotides, and of the role of molecular interaction in biosensing performanceA CMOS Label-free DNA Sensor using Electrostatic Induction of Molecular Charges
28 October 2011, 20:46:12
Publication year: 2011
Source: Biosensors and Bioelectronics, Available online 28 October 2011
Kang-Ho Lee, Jeong Oen Lee, Sukhwan Choi, Jun-Bo Yoon, Gyu-Hyeong Cho
This paper reports a label-free biosensor for the detection of DNA hybridization. The proposed biosensor measures the surface potential on oligonucleotide modified electrodes using a direct charge accumulation method. The sensor directly and repeatedly measures the charges induced in the working electrode, which correspond to intrinsic negative charges in immobilized molecules. The sensor achieves an improved signal-to-noise ratio (SNR), through the oversampling effect of accumulation for charges and the differential architecture. The sensor also shows stable, robust, and reproducible measurement independent of slight changes in the reference voltage, unlike previous ion-sensitive field effect transistors (ISFETs), providing the benefits of choosing a wide variety of reference electrode materials. The proposed device is integrated with working electrodes, a reference electrode and readout circuits into one package via a 0.35 μm complementary metal-oxide-semiconductor (CMOS) process. The sensor achieves a detectable range of 88.3 dB and a detection limit of 36 μV for surface potential. It is demonstrated that the sensor successfully achieves specific detection of oligonucleotide sequences derived from the H5N1 avian influenza virus. The experiments show a limit of detection of 100 pM and include a single-base mismatch test in 18-mer oligonucleotides.Index Terms- DNA hybridization, negative charge, FET sensor, accumulation
Source: Biosensors and Bioelectronics, Available online 28 October 2011
Kang-Ho Lee, Jeong Oen Lee, Sukhwan Choi, Jun-Bo Yoon, Gyu-Hyeong Cho
This paper reports a label-free biosensor for the detection of DNA hybridization. The proposed biosensor measures the surface potential on oligonucleotide modified electrodes using a direct charge accumulation method. The sensor directly and repeatedly measures the charges induced in the working electrode, which correspond to intrinsic negative charges in immobilized molecules. The sensor achieves an improved signal-to-noise ratio (SNR), through the oversampling effect of accumulation for charges and the differential architecture. The sensor also shows stable, robust, and reproducible measurement independent of slight changes in the reference voltage, unlike previous ion-sensitive field effect transistors (ISFETs), providing the benefits of choosing a wide variety of reference electrode materials. The proposed device is integrated with working electrodes, a reference electrode and readout circuits into one package via a 0.35 μm complementary metal-oxide-semiconductor (CMOS) process. The sensor achieves a detectable range of 88.3 dB and a detection limit of 36 μV for surface potential. It is demonstrated that the sensor successfully achieves specific detection of oligonucleotide sequences derived from the H5N1 avian influenza virus. The experiments show a limit of detection of 100 pM and include a single-base mismatch test in 18-mer oligonucleotides.Index Terms- DNA hybridization, negative charge, FET sensor, accumulation
No comments:
Post a Comment