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.
Colloids Surf B Biointerfaces. 2013 Apr 1;104:181-5. doi: 10.1016/j.colsurfb.2012.12.009. Epub 2012 Dec 20.
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).
为了构建三维电极，在金电极上进行了金纳米粒子的原位电化学沉积，该金电极涂有 3-巯基丙酸自组装单层（Au NP/MPA/Au）。然后将辣根过氧化物酶（HRP）固定在这个三维电极中，实现了 HRP 的直接电子转移。扫描电子显微镜和电化学阻抗谱用于表征 HRP 固定前后的电极。在 Au NP/MPA/Au 电极上固定 HRP 的表观米氏常数为 0.78 mM，表明 HRP 具有很高的酶活性。HRP 修饰电极进一步用作用于电催化还原和检测过氧化氢的传感平台。在该电极上检测过氧化氢时，灵敏度为 311.72 μA mM(-1) cm(-2)，检测限为 0.16 μM，动态范围为 0.48 μM 至 1.2 mM。因此，该电极是一种用于灵敏和可重现检测 H(2)O(2)的有前途的装置。
