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Amperometric Biosensor for Hydrogen Peroxide Based on Electrodeposited Sub‐micrometer Gold Modified Glassy Carbon Electrode
Author(s) -
Wang ShuQing,
Chen Jun,
Lin XiangQin
Publication year - 2004
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.20040220409
Subject(s) - chemistry , amperometry , ascorbic acid , biosensor , hydrogen peroxide , detection limit , glassy carbon , thionine , electrode , electrochemistry , horseradish peroxidase , electrochemical gas sensor , analytical chemistry (journal) , inorganic chemistry , nuclear chemistry , cyclic voltammetry , chromatography , organic chemistry , biochemistry , food science , enzyme
A new type of hydrogen peroxide amperometric biosensor was fabricated based on electrochemically deposited sub‐micrometer Au particles (sm‐Au) on a glassy carbon electrode (GCE). Electrochemical deposition condition was optimized for obtaining uniformly distributed sub‐micrometer sized Au array on the electrode surface. The hydrogen peroxide sensor was fabricated by adsorbing phenothiazine methylene blue (MB) molecules on the surface of sm‐Au and covering a cross‐linked horseradish peroxidase (HRP) layer, labeled as HRP/MB/sm‐Au/GCE. The characteristics of this biosensor were evaluated with respect to applied potential and pH. The amperometric response of the sensor was linear to the H 2 O 2 concentration over a wide range of 9.9×10 −6 —1.11×10 −2 mol/L. A detection limit ( s/n=3 ) of 3.0×10 −6 mol/L H 2 O 2 was estimated for a sampled chronoamperometric detection at 1.5 min after potential step of 200 to −400 mV vs. SCE. The immobilized MB molecules shuttled electrons at α = 0.77 and an apparent electron transfer rate constant of k 0 5 =0.053 s −1 . Interference of ascorbic acid, dopamine and uric acid was investigated. This sensor has very good stability and reproducibility for long‐term use.