The fabrication and characterization of a bismuth nanoparticle modified boron doped diamond electrode and its application to the simultaneous determination of cadmium(II) and lead(II)

Toghill, Kathryn E. and Wildgoose, Gregory G. and Moshar, Amir and Mulcahy, Chris and Compton, Richard G. (2008) The fabrication and characterization of a bismuth nanoparticle modified boron doped diamond electrode and its application to the simultaneous determination of cadmium(II) and lead(II). Electroanalysis, 20 (16). pp. 1731-1737. ISSN 1040-0397

Abstract

We report the simultaneous electroanalytical determination of Pb2+ and Cd2+ by square-wave anodic stripping voltammetry (SWASV) using a bismuth nanoparticle modified boron doped diamond (Bi-BDD) electrode. Bi deposition was performed in situ with the analytes, from a solution of 0.1 rnM Bi(NO3)(3) in 0.1 M HClO4, (pH 1.2), and gave detection limits of 1.9 mu g L-1 and 2.3 mu g L-1 for Pb(II) and Cd(II) respectively. Pb2+ and Cd2+ could not be detected simultaneously at a bare BDD electrode, whilst on a bulk Bi macro electrode (BiBE) the limits of detection for the simultaneous determination of Pb2+ and Cd2+ were ca. ten times higher. In situ atomic force microscopy (AFM) was performed to characterize the Bi nanoparticle growth on the BDD surface over a period of 120 s. The average final size of the Bi nanoparticles was 45 +/- 25 nm in height with a number density on the electrode surface of ca. 7 x 10(9) np/cm(2) obtained. The in situ AFM characterization suggests that the Bi nanoparticles are deposited by an "instantaneous" nucleation and growth mechanism.