微波-伏安法协同体系应用于水体中痕量Pb(Ⅱ)的检测研究

Study on Microwave Irradiated-Voltammetry Synergetic System for the Detection of Trace Pb(Ⅱ) in Water

采用金纳米粒子修饰铂微电极(Au-NPs/Pt)为"探针",研究其在微波-伏安法协同体系下检测Pb(Ⅱ)的电化学性质.微波辐射的"自聚焦"作用导致微电极/电解质扩散层形成"热点效应"、温度梯度和对流传质.采用单电子氧化还原Fe(CN)64-/3-/K2SO4(pH 3)体系对电极/电解质界面温度进行校正.研究结果发现,低功率微波对Au-NPs/Pt微电极的电化学性质影响较为明显.采用微波-伏安法检测Pb(II)的溶出电流极大增强,比传统方法增大近10倍.常规条件下易于阻塞电极的表面活性剂在微波-伏安协同体系中对Pb(Ⅱ)峰电流的影响也大大减小.

Gold nanoparticles-modified platinum（Au-NPs/Pt） microelectrode is used as a ＂probe＂,and applied to detect Pb（II） in the presence of microwave irradiated-voltammetry synergetic system.Self-focusing of the microwave radiation creates a ＂hot spot＂ at the electrode/electrolyte interface within the diffusion layer of the electrode with an inverted thermal gradient and convective flow.The temperature at the electrode/solution interface is calibrated with reversible one electron redox system in aqueous K2SO4 solution（pH 3）.The results indicate that the electrochemical performance at the Au-NPs/Pt microelectrode is significantly affected under the low microwave power.The Pb（II） stripping current at the（Au-NPs/Pt） microelectrode is shown to be strongly enhanced by microwave irradiated-voltammetry,which triggers approximately 10-times Pb（II） current response compared to those expected values in conventional conditions.The effect of surfactant,which blocks the electrochemical Pb（II） signal under conventional conditions,is remarkably reduced under the microwave radiation of voltammetry process.