Performance comparison of simultaneo us detection Heavy-Metal ions based on carbon materials electrochemical sensor

Abstract

In this study, oak biomass carbon (BC) and BC-Au composite materials were synthesized by the pyrolysis method to construct BC-Au electrode and ionic liquid carbon paste electrode (CILE) composed of BC, graphite and 1-octyl-3-methylimidazolium hexafluorophosphate(IL) for simultaneous detection of Cd2+, Pb2+ and Hg2+. The obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectrum (Raman). The electrochemical performance of two sensors was studied using square wave voltammetry (SWV), cyclic voltammetry (CV), electrochemical impedance methods (EIS) and linear sweep voltammetry (LSV). The obtained results show that the detection performance of CILE was clearly better than BC-Au in terms of wide linear range(0.5 µM to 6.0 µM for Cd2+, Pb2+ and Hg2+) and high sensitivity(the detection limit toward Cd2+, Pb2+ and Hg2+ is 0.09 µM, 0.366 µM and 0.489 µM, respectively). In addition, a portable electrochemical sensing device matched with one-off CILE was constructed, which would enhance the ability for multiple electrochemical detection situations and show prospective applications for the detection of Cd2+, Pb2+ and Hg2+ in real lakes and cucumber samples.