A Highly Sensitive Electrochemical Impedimetric Nanobiosensor for Dust Mite Antigen Der p2 Detection

2011 ◽  
Author(s):  
I-Jiuan Bau ◽  
Gou-Jen Wang
Keyword(s):  
Gold Nanoparticles ◽  
Electrochemical Deposition ◽  
Barrier Layer ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Sensing Element ◽  
Self Assembled Monolayer ◽  
Highly Sensitive ◽  
Der P2 ◽  
Dust Mite

The group 2 allergen, Der p2, has been reported to activate innate toll-like receptors (TLRs) on respiratory epithelial cells and thus aggravate respiratory diseases. In this study, a high sensitive nanobiosensor based on a 3D sensing element that has uniformly deposited gold nanoparticles for the detection of the dust mite antigen Der p2 is proposed. The barrier layer of an anodic aluminum oxide (AAO) film is used as the template in this highly sensitive nanobiosensor fabricated with a reducing agent and stabilizer-free method. Electrochemical deposition is utilized to synthesize uniformly distributed gold nanoparticles on the surface of the barrier layer. The size and the distribution density of the nanoparticles can be well controlled by the potential applied during electrochemical deposition. Following this procedure, monoclonal antibodies were immobilized against the dust mite antigen Der p2 by the gold nanoparticles through the 11-MUA (11-mercaptoundecanoic acid), EDC (1-Ethyl-3-(3-dimethyl-aminopropyl)-carbodiimide)/NHS (N-hydroxysuccinimide) self-assembled monolayer approach. The proposed nanobiosensor was successfully used to examine the Der p2 down to a concentration of 1pg/mL through the electrochemical impedance spectroscopy analysis. The high sensitivity of the proposed 3D nanobiosensor can be attributed to the high intensity and uniformity of the Au nanoparticles on the sensor. The proposed nanobiosensor would be useful for the fast detection of rare molecules in a solution.

A highly sensitive glucose sensor based on a gold nanoparticles/polyaniline/multi-walled carbon nanotubes composite modified glassy carbon electrode

2018 ◽  
Vol 42 (14) ◽  
pp. 11944-11953 ◽  
Author(s):  
Xinping Zeng ◽  
Yazhou Zhang ◽  
Xiling Du ◽  
Yanfei Li ◽  
Wenwei Tang
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Glucose Sensor ◽  
High Sensitivity ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Highly Sensitive ◽  
Multi Walled Carbon Nanotubes ◽  
Application Potential ◽  
Walled Carbon Nanotubes

The PTFE/GOx/AuNPs/PANI/MWCNTs/GCE glucose sensor possesses wide linear range, low detection limit, high sensitivity, which can measure the glucose in human serum and holds application potential.

scholarly journals Functionalized Carbon Nanotubes with Gold Nanoparticles to Fabricate a Sensor for Hydrogen Peroxide Determination

2012 ◽  
Vol 9 (4) ◽  
pp. 2540-2549 ◽  
Author(s):  
Halimeh Rajabzade ◽  
Parandis Daneshgar ◽  
Elham Tazikeh ◽  
Ramin Zafar Mehrabian
Keyword(s):  
Hydrogen Peroxide ◽  
Gold Nanoparticles ◽  
Ionic Liquid ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Applied Potential ◽  
Carbon Paste ◽  
Experimental Conditions ◽  
Highly Sensitive ◽  
The Matrix

A highly sensitive electrode was prepared based on gold nanoparticles/nanotubes/ionic liquid for measurement of Hydrogen peroxide. Gold nanoparticles of 20–25 nm were synthesized on a nanotube carbon paste electrode by cyclic voltammetry technique while the coverage was controlled by applied potential and time. The gold nanoparticles were modified to form a monolayer on CNT, followed by decoration with ionic liquid for determination of hydrogen peroxide. The experimental conditions, applied potential and pH, for hydrogen peroxide monitoring were optimized, and hydrogen peroxide was determined amperometrically at 0.3 V vs. SCE at pH 7.0. Electrocatalytic effects of gold deposited CNT were observed with respect to unmodified one. The sensitivity obtained was 5 times higher for modified one. The presence of Au particles in the matrix of CNTs provides an environment for the enhanced electrocatalytic activities. The sensor has a high sensitivity, quickly response to H2O2and good stability. The synergistic influence of MWNT, Au particles and IL contributes to the excellent performance for the sensor. The sensor responds to H2O2in the linear range from 0.02 µM to 0.3 mM. The detection limit was down to 0.4 µM when the signal to noise ratio is 3.

scholarly journals Impedimetric and Plasmonic Sensing of Collagen I Using a Half-Antibody-Supported, Au-Modified, Self-Assembled Monolayer System

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 227
Author(s):  
Marcin Gwiazda ◽  
Sheetal K. Bhardwaj ◽  
Ewa Kijeńska-Gawrońska ◽  
Wojciech Swieszkowski ◽  
Unni Sivasankaran ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Covalent Immobilization ◽  
Electrochemical Immunosensor ◽  
Collagen I ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Self Assembled Monolayer ◽  
Self Assembled

This research presents an electrochemical immunosensor for collagen I detection using a self-assembled monolayer (SAM) of gold nanoparticles (AuNPs) and covalently immobilized half-reduced monoclonal antibody as a receptor; this allowed for the validation of the collagen I concentration through two different independent methods: electrochemically by Electrochemical Impedance Spectroscopy (EIS), and optically by Surface Plasmon Resonance (SPR). The high unique advantage of the proposed sensor is based on the performance of the stable covalent immobilization of the AuNPs and enzymatically reduced half-IgG collagen I antibodies, which ensured their appropriate orientation onto the sensor’s surface, good stability, and sensitivity properties. The detection of collagen type I was performed in a concentration range from 1 to 5 pg/mL. Moreover, SPR was utilized to confirm the immobilization of the monoclonal half-antibodies and sensing of collagen I versus time. Furthermore, EIS experiments revealed a limit of detection (LOD) of 0.38 pg/mL. The selectivity of the performed immunosensor was confirmed by negligible responses for BSA. The performed approach of the immunosensor is a novel, innovative attempt that enables the detection of collagen I with very high sensitivity in the range of pg/mL, which is significantly lower than the commonly used enzyme-linked immunosorbent assay (ELISA).

Electrokinetics-Based Microfluidic Technology for the Rapid Separation and Concentration of Bacteria/Cells/Biomolecules

2014 ◽  
Vol 911 ◽  
pp. 347-351 ◽  
Author(s):  
I Fang Cheng ◽  
Tzu Ying Chen ◽  
Hsien Chang Chang
Keyword(s):  
Cancer Cell ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
High Specificity ◽  
Cell Detection ◽  
Label Free ◽  
Rapid Separation ◽  
Whole Cells ◽  
Highly Sensitive ◽  
Label Free Detection

Conventional techniques for detection of bacteria/cell and assessment of cancer cell typically use DNA techniques, Western blot and ELISA kits that are high cost, complicated processes and long time consuming. Our researches focus on rapid, portable, simple and highly sensitive separation and detection of cells/bacteria/biomolecules for field-use diagnosis. An ideal portable biosensor (molecular or whole cells detections) unit must have several important features: rapid detection time (<10 minutes), high sensitivity (pM level for molecular detection, 103 cells/ml for whole cell detection), high specificity, small and inexpensive instrumentation configuration. Electrochemical impedance/conductance sensing is preferred over optical detection because of cost and portability concerns. Cancer cell detection using heterogeneous medical samples require continuous isolation, sorting, and trapping of the target bioparticles and immunocolloids within a diagnostic chip. We have developed several electrokinetic strategies to rapid separation, concentration and detection of cells/bacteria/biomolecules in a microfluidic chip using such as dielectrophoresis (DEP), traveling-wave dielectrophoresis (twDEP) and electrohydrodynamics (EHD). Several key techniques we done, which on a rapid/simple/label-free detection platform for the highly sensitive on-chip separation/identification/quantification will be introduced in this paper.

Highly sensitive colorimetric determination of malathion using gold nanoparticles

2016 ◽  
Vol 16 (5) ◽  
pp. 1214-1220 ◽  
Author(s):  
Tayebeh Kohzadi ◽  
Mahmoud Roushani
Keyword(s):  
Gold Nanoparticles ◽  
High Sensitivity ◽  
Colorimetric Determination ◽  
Good Precision ◽  
Buffer Solution ◽  
Microscopy Technique ◽  
Resonance Band ◽  
Highly Sensitive ◽  
Agriculture Products

A highly sensitive method is presented for the colorimetric determination of malathion using gold nanoparticles (AuNPs). In this approach, the synthesized AuNPs solution was stabilized by the citrate anions as their repulsion protected the AuNPs from aggregation. The synthesized AuNPs were characterized morphologically by using transmission electron microscopy technique. Malathion caps the surface of AuNPs and induces the aggregation of AuNPs in Britton–Robinson buffer solution. The reaction was monitored spectrophotometrically by measuring the decrease in the plasmon resonance band of the AuNPs at 527 nm after 9 min. The effect of reaction variables on the reaction sensitivity was investigated and furthermore, the interference of common ions was effectively avoided. The calibration curve is linear over the concentration range 3.3 × 10−7 to 3.3 × 10−6 mol/L of malathion with good precision and accuracy and the detection limit was down to 1.5 × 10−7 mol/L. The developed approach does not use complex and expensive instruments. The high sensitivity of the proposed method allowed its successful application to wheat and water samples. Thus, the proposed strategy can serve as a powerful method for the rapid diagnosis of malathion in agriculture products.

scholarly journals A template/electrochemical deposition method for fabricating silver nanorod arrays based on porous anodic alumina

2017 ◽  
Vol 7 ◽  
pp. 184798041771754 ◽  
Author(s):  
Yafang Li ◽  
Jie Xu ◽  
Hao Liu ◽  
Jinzhong Song ◽  
Yashuang Li ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Barrier Layer ◽  
Electrochemical Impedance ◽  
Average Diameter ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Nanorod Arrays ◽  
Deposition Method ◽  
Electrochemical Deposition Method ◽  
Anodic Alumina Templates

A template/electrochemical deposition method for fabricating silver nanorod arrays based on porous anodic alumina was presented. The barrier layer of porous anodic alumina templates was thinned by step-by-step voltage decrement method. Subsequently, silver ions were reduced into the channels of porous anodic alumina templates by electrochemical deposition method. Electrochemical impedance spectroscopy was utilized for analyzing the thickness of barrier layer of porous anodic alumina templates; the elementary composition and the size of silver nanorod arrays were characterized by X-ray diffraction and field-emission scanning electron microscope, respectively. Experimental results showed that the thickness of barrier layer of porous anodic alumina was suitable for alternating current electrochemical deposition, when anodizing potential was decreased to 70 V and widening time of porous anodic alumina in H3PO4 solution is 80 min. And the silver particles could be deposited into the channels of porous anodic alumina templates at 11 V, 13 V, and 15 V. Different sizes of silver nanorod arrays were obtained by controlling the deposition time. The average diameter of silver nanorod is in the range from 346 nm to 351 nm which is almost consistent with the pore diameter of porous anodic alumina templates (367 nm). The uniform silver nanorod arrays have a considerable potential in the flexible and wearable electronic devices, optics, solar cell, the catalytical electrode, and so on.

Genetically Modified Soybean Detection Using a Biosensor Electrode With Self-Assembled Gold Nanoparticles on a Micro Hemisphere Array

2019 ◽  
Author(s):  
Ying-Ting Lin ◽  
Iren Kuznetsova ◽  
Gou-Jen Wang
Keyword(s):  
Gold Nanoparticles ◽  
Electrochemical Impedance ◽  
Genetically Modified ◽  
Cost Effective ◽  
Ethanol Solution ◽  
Gold Layer ◽  
Self Assembled Monolayer ◽  
Genetically Modified Soybean ◽  
Ordered Array ◽  
Self Assembled

Abstract Gene transfer technology changes some of the characteristics of crops. However, genetically modified foods have been reported to have an impact on human health. We proposed a cost effective and highly sensitive biosensor electrode with self-assembled monolayer of gold nanoparticle on a micro hemisphere array to detect genetically modified soybean. An ordered array of micro hemispherical features was formed on a 6-inch reclaimed silicon wafer using photolithography. Then, a thin gold layer was sputtered onto the hemispheres. The wafer was then immersed into a 5 mM ethanol solution of 1,6-hexanedithiol (1,6-HDT) to enable the attachment of one thio-end of 1,6-HDT to the thin gold layer. Next, a colloidal gold (15 nm) solution was dripped onto the wafer and baked on a hot plate in such a way that the monolayer of gold nanoparticles could self-assemble on the 1,6-HDT surface. Finally, we used electrochemical impedance spectroscopy (EIS) analysis to detect genetically modified soybean. Experimental results demonstrate that our biosensor can successfully distinguish the genetically modified soybeans from the normal ones.

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