Electrochemical determination of lead(II) on modified gold electrode by square wave voltammetry

Toxic heavy metals pose a great threat to living organisms due to their nonbiodegradability and persistence [1, 2]. Over the past few decades, there has been an increasing interest in the development of highly sensitive analytical methods for the detection of trace amounts of toxic heavy metals. Electrochemical detection of heavy metals offers several advantages such as simplicity, accurateness, low-cost, remarkable sensitivity and high stability. Square-wave voltammetry (SWV) has been widely recognized as a powerful technique for the determination of trace metal ions. In this study, A sensitive method for the electrochemical determination of Pb(II) in acidic aqueous solution has been developed based on a gold electrode modified with [(L-Cys)3PW12O40] using SWV. [(L-Cys)3PW12O40] has been prepared by solvent free reaction at room temperature and structurally characterized by an elemental analysis, FT-IR spectroscopy and UV-Vis absorption spectroscopy. The conditions for the prepared electrode were optimized. Under the optimum conditions, a linear relationship existed between the current and the concentration of Pb(II) in the range between 1.0– 200.0 μM with the detection limits of 760 nM, based on a signal-tonoise ratio equal to 3 (S/N = 3).