复合纳米微粒修饰丝网印刷电极的一次性过氧化氢生物传感器研究

Study on a disposable hydrogen peroxide biosensor based on Au-graphene-HRP-Nafion biocomposites modified screen-printed carbon electrodes

构建纳米金(Au)-石墨烯(GS)-辣根过氧化物酶(HRP)-Nafion纳米复合物修饰丝网印刷电极(SPCEs)的一次性过氧化氢生物传感器,并用于过氧化氢的测定。采用化学镀金方法于SPCEs表面形成Au,然后将GS、HRP和Nafion组成的复合物涂覆于SPCEs/Au表面,构建SPCEs/Au/GS/HRP/Nafion电极,采用扫描电镜(SEM)表征化学镀金、GS和电极的制备过程,采用循环伏安(CV)法和计时电流(i-t)法研究H2O2的电化学性质。在优化的实验条件下,该电极能实现HRP的直接电子传递,对H2O2有显著的电催化作用,在2.0×10-5～2.5×10-3mol/L浓度范围内对H2O2有良好的线性响应,线性相关系数为0.9994,检测限为1.2×10-5mol/L。该传感器灵敏快速、制备容易、样品用量少、可抛弃、抗干扰性强,有望用于食品中痕量HO残留的检测。

A disposable biosensor for determination of hydrogen peroxide（H2O2） based on gold nanoparticles（Au）-graphene sheets（GS）-horseradish peroxidase（HRP）-Nafion biocomposites modified screen-printed carbon electrodes（SPCEs） was fabricated.To construct the H2O2 biosensor,GS and HRP were co-immobilized into biocompatible Nafion,then the SPCEs was modified by the biocomposite,followed by electroless plating of Au on the surface to fabricate SPCEs/Au/GS/HRP/Nafion electrode.Different technologies were employed to study the synthesis of GS,construction processes and the electrochemical properties of the biosensor.Under the optimized experimental conditions,Cyclic voltammetry（CV） demonstrated that the direct electron transfer（DET） of HRP was realized,and the biosensor had an excellent performance in terms of electrocatalytic reduction towards H2O2.The linear response of the biosensor to H2O2 was in the concentration range of 2.0×10-5～2.5×10-3mol/L（R2=0.9994） with a detection limit of 1.2×10-5mol/L.The proposed electrochemical biosensor was sensitive,quickly,disposable with low cost,fewer sample volume,easy preparation and strong anti-interference,which shows great promise for screen-determination of trace H2O2 in real samples.