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).

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.

Synthesis of NiO Electrochromic Films via Two-Step Method

2014 ◽  
Vol 894 ◽  
pp. 381-385 ◽  
Author(s):  
Siti Zairyn Fakurol Rodzi ◽  
Yusairie Mohd
Keyword(s):  
Thin Films ◽  
Optical Quality ◽  
Step Method ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Ito Glass ◽  
Uv Visible ◽  
Electrodeposition Of Nickel

Nickel oxide thin films were electrodeposited onto ITO glass substrates by a two-step method: i) electrodeposition of nickel and ii) further thermal oxidation at 300 °C. The surface morphology of the NiO thin films was characterized by atomic force microscopy (AFM) and the transmittance in the coloured and bleached states were analysed using UV-Visible (UV-Vis) spectroscopy. The electrochemical properties of NiO films were measured in 1 M KOH electrolyte by cyclic voltammetry (CV). A good optical quality and highly improved electrochromic performances NiO film was successfully synthesized.

Synthesis, growth mechanism and effect of sputtering pressure on 3D ZnO nanostructures with trunk-branch nanorods

2019 ◽  
Vol 12 (06) ◽  
pp. 1940003 ◽  
Author(s):  
Yangsi Liu ◽  
Wei Gao
Keyword(s):  
Growth Mechanism ◽  
Zno Nanorods ◽  
Three Dimensional ◽  
Zno Nanostructures ◽  
Seed Crystals ◽  
Glass Substrates ◽  
Growth Method ◽  
Step Growth ◽  
Sputtering Pressure ◽  
Microscopic Techniques

Three-dimensional (3D) ZnO nanostructures, hierarchical nanorods with trunks and branches, were synthesized via a multi-step growth method. The ZnO trunk-branch nanorods are immobilized on glass substrates and their fabrication technologies include the deposition of ZnO seed crystals by magnetron sputtering and the hydrothermal growth of ZnO nanorods without any directing agents. The sputtering pressure for the deposition of ZnO seed crystals was varied and the corresponding effect on the morphology and microstructure of 3D ZnO nanostructures was characterized by various spectroscopic and microscopic techniques. The growth mechanism of ZnO trunk-branch nanorods was discussed and their optical property was also explored. The multi-level constructions of ZnO nanorods would benefit their photo-related functional applications.

Interfacial Construction of Gold Nanoshells on 3-Aminopropyl Triethoxysilane Modified ITO Electrode Surface for Studying Cytochrome b562 Electrochemistry

2007 ◽  
Vol 7 (2) ◽  
pp. 440-446 ◽  
Author(s):  
Aihua Jing ◽  
Yong Tan ◽  
Yi Wang ◽  
Shaohua Ding ◽  
Weiping Qian
Keyword(s):  
Gold Nanoshells ◽  
Transfer Reactions ◽  
Cyt B ◽  
Electrochemical Behaviors ◽  
Redox Protein ◽  
Glass Substrates ◽  
Cytochrome B562 ◽  
Ito Electrode ◽  
Vis Spectroscopy ◽  
Ito Glass

An interface of gold nanoshells (GNSs) was constructed on the surface of the 3-aminopropyl triethoxysilane (APTES) modified ITO glass substrates by a simple self-assemble method to form the GNSs-coated ITO electrode. UV-vis spectroscopy, scanning electron microscopy (SEM), and cyclic voltammetry were used to characterize the GNSs interface architectures. SEM and UV-vis spectroscopy showed that an interconnected and stable GNSs interface was formed on the APTES modified ITO glass substrate. The cytochrome b562 (Cyt b562) was selected to observe electron transfer reactions of redox protein at the GNSs-coated ITO electrodes. Quasi-reversible electrochemistry of Cyt b562 was obtained and its electrochemical behaviors were discussed.

scholarly journals Effect of Chitosan Electrospun Fiber Mesh as Template on the Crystallization of Calcium Oxalate

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 453
Author(s):  
Nicole Butto ◽  
Nicole Cotrina Vera ◽  
Felipe Díaz-Soler ◽  
Mehrdad Yazdani-Pedram ◽  
Andrónico Neira-Carrillo
Keyword(s):  
Calcium Oxalate ◽  
Electrospun Fiber ◽  
Three Dimensional ◽  
Active Role ◽  
Glass Substrates ◽  
Ito Glass ◽  
Organic Matrices ◽  
Living Organisms ◽  
Xrd Techniques

Biominerals fulfill various physiological functions in living organisms, however, pathological mineralization can also occur generating mineral pathologies such as the formation of calcium oxalate (CaOx) calculi in the urinary tract. Inspired by the ability of living organisms to generate biogenic minerals using biological organic matrices, and the need to understand the mechanisms of crystallization, three-dimensional fibrillary meshes based on chitosan fibers with random and controlled topology by electrospinning were manufactured. Chitosan was selected due to its active role on in vitro crystallization and its physicochemical properties, which allows the exposure of their functional chemical groups that could selectively stabilize hydrated crystalline forms of CaOx. CaOx crystals were generated on conductive tin indium oxide (ITO) glass substrates modified with electrospun chitosan fibers by using electrocrystallization (EC) technique. The chitosan fibers and the resulting CaOx crystals were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques, which demonstrated that the chemical nature and topology of the three-dimensional fibers used as organic template are key factors in the control of type, morphology, and crystallographic orientation of CaOx.

Electrochemically Functionalized Seamless Three-Dimensional Graphene-Carbon Nanotube Hybrid for Direct Electron Transfer of Glucose Oxidase and Bioelectrocatalysis

Langmuir ◽  
2015 ◽  
Vol 31 (47) ◽  
pp. 13054-13061 ◽  
Author(s):  
Trupti Terse-Thakoor ◽  
Kikuo Komori ◽  
Pankaj Ramnani ◽  
Ilkeun Lee ◽  
Ashok Mulchandani
Keyword(s):  
Electron Transfer ◽  
Carbon Nanotube ◽  
Glucose Oxidase ◽  
Direct Electron Transfer ◽  
Three Dimensional

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

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