scholarly journals Bioelectrocatalysis of Hemoglobin on Electrodeposited Ag Nanoflowers toward H2O2 Detection

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1628
Author(s):  
Ajay Kumar Yagati ◽  
Hien T. Ngoc Le ◽  
Sungbo Cho
Keyword(s):  
Electron Transfer ◽  
Detection Limit ◽  
Indium Tin Oxide ◽  
Direct Electron Transfer ◽  
Electrochemical Measurement ◽  
Clinical Diagnostics ◽  
Detection Range ◽  
H2o2 Detection ◽  
Vis Spectroscopy ◽  
Living Organisms

Hydrogen peroxide (H2O2) is a partially reduced metabolite of oxygen that exerts a diverse array of physiological and pathological activities in living organisms. Therefore, the accurate quantitative determination of H2O2 is crucial in clinical diagnostics, the food industry, and environmental monitoring. Herein we report the electrosynthesis of silver nanoflowers (AgNFs) on indium tin oxide (ITO) electrodes for direct electron transfer of hemoglobin (Hb) toward the selective quantification of H2O2. After well-ordered and fully-grown AgNFs were created on an ITO substrate by electrodeposition, their morphological and optical properties were analyzed with scanning electron microscopy and UV–Vis spectroscopy. Hb was immobilized on 3-mercaptopropionic acid-coated AgNFs through carbodiimide cross-linking to form an Hb/AgNF/ITO biosensor. Electrochemical measurement and analysis demonstrated that Hb retained its direct electron transfer and electrocatalytic properties and acted as a H2O2 sensor with a detection limit of 0.12 µM and a linear detection range of 0.2 to 3.4 mM in phosphate-buffered saline (PBS). The sensitivity, detection limit, and detection range of the Hb/AgNF/ITO biosensor toward detection H2O2 in human serum was also found to be 0.730 mA mM−1 cm−2, 90 µM, and 0.2 to 2.6 mM, indicating the clinical application for the H2O2 detection of the Hb/AgNF/ITO biosensor. Moreover, interference experiments revealed that the Hb/AgNF/ITO sensor displayed excellent selectivity for H2O2.

Investigation of electron transfer from isolated spinach thylakoids to indium tin oxide

RSC Advances ◽  
2014 ◽  
Vol 4 (90) ◽  
pp. 48815-48820 ◽  
Author(s):  
Herlina Arianita Dewi ◽  
Fanben Meng ◽  
Barindra Sana ◽  
Chunxian Guo ◽  
Birgitta Norling ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Water Splitting ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Direct Electron Transfer ◽  
Light Irradiation ◽  
Spinach Thylakoids

The electrons generated by photosynthetic water splitting have been studied for direct electron transfer under light irradiation.

Direct Electron Transfer and Electrocatalysis of Hemoglobin Adsorbed on Coralloid Gold Nanostructures

2008 ◽  
Vol 8 (7) ◽  
pp. 3439-3446 ◽  
Author(s):  
Aihua Jing ◽  
Jian Dong ◽  
Xiaoyuan Ma ◽  
Weiping Qian
Keyword(s):  
Electron Transfer ◽  
Direct Electron Transfer ◽  
Three Dimensional ◽  
Gold Nanostructures ◽  
Electrochemical Growth ◽  
Glass Substrates ◽  
Vis Spectroscopy ◽  
Ito Glass ◽  
Growth Method ◽  
Complementary Techniques

Three-dimensional (3D) coralloid gold nanostructures (CGNs) have been fabricated by using an electrochemical growth method on the ITO glass substrates coated with agarose gel. Characterization by a variety of complementary techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-vis spectroscopy confirmed the distribution of CGNs on the ITO glass substrates. The adsorption behaviors of hemoglobin (Hb) on the CGNs-modified ITO (CGNs/ITO) electrodes were investigated by UV-vis spectroscopy and electrochemical methods, and the results demonstrated that 3D CGNs could provide good microenvironment for loading biomolecules and retaining their biological activity. Direct electron transfer of the adsorbed Hb exhibited a couple of stable and well-defined redox peaks centered at about −0.121 V and −0.041 V (vs. SCE) in 0.1 mol L−1 pH 7.0 PBS. The electron transfer rate constant is 0.78 s−1 at a scan rate of 0.1 V s−1. The adsorbed Hb in the CGNs displayed a rapid amperometric response to the reduction of hydrogen peroxide (H2O2) for a broad linear range from 1.0 × 10−6 mol L−1 to 5.0 × 10−3 mol L−1 with the detection limit of 3.0 × 10−7 mol L−1 (S/N = 3).

A Simple Hydrogen Peroxide Biosensor Based on Catalase Immobilized in Nano-Structural Composite Film

2013 ◽  
Vol 704 ◽  
pp. 258-263
Author(s):  
Zhao Hao Wang ◽  
Han Cui ◽  
Qi Jin Wan ◽  
Nian Jun Yang
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Detection Limit ◽  
Self Assembly ◽  
Nanocomposite Film ◽  
Gold Electrode ◽  
Multilayer Film ◽  
Au Nanoparticles ◽  
Direct Electron Transfer ◽  
Structural Composite

A robust and effective nanocomposite film modified gold electrode based on 2, 3-dimercaptosuccinic acid (DMSA) and Au nanoparticles (AuNPs) was prepared by a method combining self-assembly with underpotential deposition. Direct electron transfer can easily take place between a gold electrode and catalase molecules anchored on AuNPs films. Besides, the CAT/AuNPs/DMSA multilayer film had a relatively rapid and satisfactory response toward H2O2 with a wide linear range from 3.0×106 to 5.86×103 M and a low detection limit of 3.0 μM (S/N = 3). The Michaelis-Menten constant of the immobilized CAT was calculated to be 2.2 mM. The simple CAT/AuNPs/DMSA/Au system can be developed into a H2O2 biosensor.

ZnO Nanonails: Synthesis and Their Application as Glucose Biosensor

2008 ◽  
Vol 8 (6) ◽  
pp. 3216-3221 ◽  
Author(s):  
Ahmad Umar ◽  
M. M. Rahman ◽  
S. H. Kim ◽  
Y. B. Hahn
Keyword(s):  
Electron Transfer ◽  
Zinc Oxide ◽  
Detection Limit ◽  
Electrode Surface ◽  
Active Sites ◽  
Thermal Evaporation ◽  
Direct Electron Transfer ◽  
High Sensitivity ◽  
Glucose Biosensor ◽  
Evaporation Process

Well-crystallized zinc oxide nanonails were grown in a high density by thermal evaporation process and were used as supporting matrixes for glucose oxidase (GOx) immobilization to construct efficient glucose biosensor. The GOx attached to the surfaces of ZnO nanonails had more spatial freedom in its orientation, which facilitated the direct electron transfer between the active sites of immobilized GOx and electrode surface. The fabricated biosensor showed a high sensitivity of 24.613 μA cm–2 mM–1 with a response time less than 10 s. Moreover, it shows a linear range from 0.1 to 7.1 mM with a correlation coefficient of R = 0.9937 and detection limit of 5 μM.

scholarly journals Low Surface Roughness Graphene Oxide Film Reduced with Aluminum Film Deposited by Magnetron Sputtering

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1428
Author(s):  
Xiaowei Fan ◽  
Xuguo Huai ◽  
Jie Wang ◽  
Li-Chao Jing ◽  
Tao Wang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Electron Transfer ◽  
Graphene Oxide ◽  
Magnetron Sputtering ◽  
Chemical Reduction ◽  
Graphene Film ◽  
Conductivity Measurement ◽  
Electrical Conductivity Measurement ◽  
Vis Spectroscopy ◽  
Hcl Solution

Graphene film has wide applications in optoelectronic and photovoltaic devices. A novel and facile method was reported for the reduction of graphene oxide (GO) film by electron transfer and nascent hydrogen produced between aluminum (Al) film deposited by magnetron sputtering and hydrochloric acid (HCl) solution for only 5 min, significantly shorter than by other chemical reduction methods. The thickness of Al film was controlled utilizing a metal detection sensor. The effect of the thickness of Al film and the concentration of HCl solution during the reduction was explored. The optimal thickness of Al film was obtained by UV-Vis spectroscopy and electrical conductivity measurement of reduced GO film. Atomic force microscope images could show the continuous film clearly, which resulted from the overlap of GO flakes, the film had a relatively flat surface morphology, and the surface roughness reduced from 7.68 to 3.13 nm after the Al reduction. The film sheet resistance can be obviously reduced, and it reached 9.38 kΩ/sq with a high transmittance of 80% (at 550 nm). The mechanism of the GO film reduction by electron transfer and nascent hydrogen during the procedure was also proposed and analyzed.

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