title: In situ synthesized gold nanoparticles for direct electrochemistry of horseradish peroxidase.
abstract: In order to construct a three-dimensional electrode, in situ electrochemical deposition of gold nanoparticles onto a gold electrode coated with a self-assembled monolayer of 3-mercaptopropionic acid (Au NP/MPA/Au) was conducted. Horseradish peroxidase (HRP) was then immobilized into this three-dimensional electrode, leading to the realization of direct electron transfer of HRP. Scanning electron microscopy and electrochemical impedance spectroscopy were applied to characterize the electrode before and after HRP immobilization. The apparent Michaelis-Menten constant for immobilized HRP on a Au NP/MPA/Au electrode is 0.78 mM, indicating high enzymatic activity of HRP. The HRP modified electrode was further utilized as a sensing platform for the electrocatalytic reduction and detection of hydrogen peroxide. For the detection of hydrogen peroxide on this electrode, the sensitivity is 311.72 μA mM(-1) cm(-2), the detection limit is 0.16 μM, and the dynamic range is from 0.48 μM to 1.2 mM. Therefore this electrode is a promising device for sensitive and reproducible detection of H(2)O(2).
authors: School of Chemical Engineering & Pharmacy, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Lab of Novel Reactor & Green Chemical Technology, Wuhan Institute of Technology, Wuhan 430073, China. qijinwan@mail.wit.edu.cn
authors: Qijin
authors: Q
authors: Wan
authors: Hongtu
authors: H
authors: Song
authors: Hao
authors: H
authors: Shu
authors: Zhaohao
authors: Z
authors: Wang
authors: Jing
authors: J
authors: Zou
authors: Nianjun
authors: N
authors: Yang
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D006046:Gold; D015097:3-Mercaptopropionic Acid; D006735:Horseradish Peroxidase