Wide linear range nanomaterial/ionophore-based electrode used for determination of lead in environmental and biological samples with differential pulse voltammetry

Abstract

A new chemically modified carbon paste electrode is fabricated to determine lead ion concentration in its trace level in aqueous media with differential pulse voltammetry (DPV). The best performance is obtained by the carbon paste electrode composition including 20% of dithiodibezoic acid (DDA), 80% of high purity graphite powder and 60 µL of colloidal gold nanoparticle (AuNP) solution. The proposed electrode has a wide linear calibration response from 1 × 10⁻⁹ to 6 × 10⁻⁵ M with a detection limit of 6.6 × 10⁻¹⁰ M, at pH 3.5. Seven replicate determination of 5 × 10⁻⁸ M of lead ion concentration gives a relative standard deviation of 3.33%. The modified sensor is applied to determine lead contents in some environmental and biological Samples with satisfactory results.

Keywords:

• modified electrode
• gold nanoparticle
• dithiodibenzoic acid
• voltammetry