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A Highly Sensitive Hydrogen Peroxide Biosensor Based on Hemoglobin Immobilized on Cadmium Sulfide Quantum Dots/Chitosan Composite Modified Glassy Carbon Electrode
Author(s) -
Butwong Nutthaya,
Zhou Lin,
Moore Eric,
Srijaranai Supalax,
Luong John H. T.,
Glen Jeremy D.
Publication year - 2014
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201400353
Subject(s) - biosensor , detection limit , nanocomposite , chitosan , cadmium sulfide , hydrogen peroxide , adsorption , chemistry , nuclear chemistry , amperometry , nafion , inorganic chemistry , electrode , materials science , electrochemistry , nanotechnology , chromatography , organic chemistry
Abstract An L ‐cysteine capped cadmium sulfide‐chitosan nanocomposite has been synthesized, characterized and used for surface modification of a glassy carbon electrode. With direct electron transfer, hemoglobin (Hb) adsorbed strongly on the nanocomposite and displayed excellent bioelectrocatalysis for H 2 O 2 . The biosensor was capable of reducing H 2 O 2 at −0.35 V, with a detection limit of 3.13 nM, linearity in the range of 15 nM to 10 µM and a response time of less than 2 s. The MichaelisMenten constant ( K M ) was 0.57 nM, attesting high bioelectrocatalysis of immobilized Hb for H 2 O 2 . Reproducibility of the fabrication method was very satisfactory with a relative standard deviation of 5.3 %. The biosensor lost only 6.5 % of its original response after 7 days when stored in a pH 7.4 PBS at 4 °C.