A Novel Hydrogen Peroxide Sensor via the Direct Electrochemistry of Horseradish Peroxidase Immobilized on Colloidal Gold Modified Screen-printed Electrode

Sensors

Xiaoxing Xu¹  Songqin Liu¹ 

[1] ¹Department of Chemistry, State Key Laboratory of Coordination Chemistry, Institute of Chemical Biology, Nanjing University, Nanjing 210093, China ²Department of Chemistry, Changshu College of Jiangsu, Changshu 215500, China

关键词: Screen-printed electrodes;    Horseradish peroxidase;    Electrocatalysis;    Colloidal gold;    Amperometric sensors;   

DOI  :  10.3390/s30900350

来源: mdpi

【 摘 要 】

The direct electrochemistry of horseradish peroxidase (HRP) immobilized on a colloidal gold modified screen-printed carbon electrode (HRP-Au-SPCE) and its application as a disposable sensor were studied. The immobilized HRP displayed a couple of stable and well-defined redox peaks with a formal potential of –0.338 V (vs. SCE) and a heterogeneous electron transfer rate constant of (0.75±0.04) s^-1 in 0.1 M pH 7.0 PBS. It showed a highly thermal stability, fast amperometric response and an electrocatalytic activity to the reduction of hydrogen peroxide (H2O2) without the aid of an electron mediator. The biosensor exhibited high sensitivity, good reproducibility, and long-term stability for the determination of H₂O₂ with a linear range from 0.8 μM to 1.0 mM and a detection limit of 0. 4 μM at 3σ. The variation coefficients are 2.7 % and 2.3 % for over 10 successive assays at the H₂O₂ concentrations of 8.0 and 20 μM, respectively. The K M app for H2O2 sensor was determined to be 1.3 mM.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.