Direct electrochemistry of hemoglobin immobilized on CdS:Mn nanoparticles

作者：Pan, Zhong-Qin; Fan, Hong; Shi, Chuan-Guo; Bao, Ning; Yu, Chun-Mei; Gu, Hai-Ying^*

来源：Microchimica Acta, 2011, 173(3-4): 277-283.

DOI：10.1007/s00604-011-0559-6

• Hemoglobin
• CdS:Mn nanoparticles
• Biosensor
• Hydrogen peroxide
• Direct electron transfer

Hemoglobin (Hb) was immobilized on CdS:Mn nanoparticles (NPs) capped with citrate to obtain an amperometric biosensor for determination of hydrogen peroxide (H2O2). The NPs were prepared from aqueous solution via a precipitation method. The UV-vis spectra of the film with Hb on the NPs and of free Hb solutions suggested that Hb retained its bioactivity and native conformation in the film. In buffer of pH 7.0, the sensor film exhibited a pair of quasi-reversible redox peaks originating from the Hb-heme Fe(III)/Fe(II) redox couple. The formal potential of Hb varied linearly with the increase of pH from 3.0 to 9.0 with a slope of -46 mV center dot pH(-1), this indicating that one proton participates in the redox reaction. The electron transfer rate constant (k(s)) is 2.2 s(-1), suggesting that the NPs provide a benign microenvironment for Hb to undergo direct electron transfer. Despite the absence of an electron mediator, the biosensor displays an analytical performance which is better than any others described in previous reports. Hence, the NPs may provide a simple and alternative approach towards electrochemical biosensors.

• 出版日期2011-6
• 单位南通大学