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

• Mixing Oak Carbon and graphite in proportion to prepare carbon paste electrode to improve its application in heavy metal detection人. • Study and explain in the change of hydrogen evolution potential of GCE and CILE in ABS. • A portable electrochemical sensing device integrating sampling, analysis and filtration is designed to realize the simultaneous detection of Cd 2+ , Pb 2+ and Hg 2+ . 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 Cd 2+ , Pb 2+ and Hg 2+ . 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 Cd 2+ , Pb 2+ and Hg 2+ ) and high sensitivity(the detection limit toward Cd 2+ , Pb 2+ and Hg 2+ 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 Cd 2+ , Pb 2+ and Hg 2+ in real lakes and cucumber samples.