Abstract: In order to realize the high sensitivity detection of glassy carbon electrode in the field of electrochemical sensors,  the glassy carbon electrode was electrochemically activated by constant potential method in phosphate buffer solution at pH=5.0. The effects of pH value,  accumulation potential and accumulation time on the detection effect of Pb²⁺ were investigated, and the detection performance of activated electrode for Pb²⁺ was investigated under the optimal experimental conditions. The experimental results show that the activated electrode can enhance the response current of electrochemical detection of Pb²⁺, and has the characteristics of short detection time and high sensitivity. The detection linear range of Pb²⁺ is 1×10^-10—5×10^-6 mol/L,  the minimum detection limit is 3×10^-11 mol/L,  and the limit of quantification is 1.0×10^-10 mol/L. The activated electrode has a high recovery in the determination of  Pb²⁺ in tap water, and can be used in the actual water quality detection.

Key words: lead ion,  , electrochemical sensor,  , glassy carbon electrode,  , differential pulse voltammetry