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Direct Electrochemistry of Hemoglobin at a Graphene Gold Nanoparticle Composite Film for Nitric Oxide Biosensing
College of Environmental Science and Engineering, Anhui Normal University, Wuhu 241000, China
* Author to whom correspondence should be addressed.
Received: 11 April 2013; in revised form: 13 May 2013 / Accepted: 3 June 2013 / Published: 7 June 2013
Abstract: A simple two-step method was employed for preparing nano-sized gold nanoparticles-graphene composite to construct a GNPs-GR-SDS modified electrode. Hemoglobin (Hb) was successfully immobilized on the surface of a basal plane graphite (BPG) electrode through a simple dropping technique. Direct electrochemistry and electrocatalysis of the hemoglobin-modified electrode was investigated. The as-prepared composites showed an obvious promotion of the direct electro-transfer between hemoglobin and the electrode. A couple of well-defined and quasi-reversible Hb CV peaks can be observed in a phosphate buffer solution (pH 7.0). The separation of anodic and cathodic peak potentials is 81 mV, indicating a fast electron transfer reaction. The experimental results also clarified that the immobilized Hb retained its biological activity for the catalysis toward NO. The biosensor showed high sensitivity and fast response upon the addition of NO, under the conditions of pH 7.0, potential ‒0.82 V. The time to reach the stable-state current was less than 3 s, and the linear response range of NO was 0.72–7.92 μM, with a correlation coefﬁcient of 0.9991.
Keywords: hemoglobin; graphene; gold nanoparticles; nitric oxide; biosensor
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MDPI and ACS Style
Xu, M.-Q.; Wu, J.-F.; Zhao, G.-C. Direct Electrochemistry of Hemoglobin at a Graphene Gold Nanoparticle Composite Film for Nitric Oxide Biosensing. Sensors 2013, 13, 7492-7504.
Xu M-Q, Wu J-F, Zhao G-C. Direct Electrochemistry of Hemoglobin at a Graphene Gold Nanoparticle Composite Film for Nitric Oxide Biosensing. Sensors. 2013; 13(6):7492-7504.
Xu, Miao-Qing; Wu, Jian-Feng; Zhao, Guang-Chao. 2013. "Direct Electrochemistry of Hemoglobin at a Graphene Gold Nanoparticle Composite Film for Nitric Oxide Biosensing." Sensors 13, no. 6: 7492-7504.