Abstract
Background: The detection of heavy metals in the environment is of great importance due to their high toxicity.
Methods: A multi-step graft route was designed for anchoring thiosemicarbazide derivative (TSCD) groups onto the porous silicon (PS) surface. The reaction efficiency at each step functionalization was confirmed using FT-IR spectra, and the XPS analysis results confirmed the modification of thiosemicarbazide derivative. The morphology change of the modified PS was studied by AFM characterization.
Results: The results display that the currents of Pb0 oxidation increase with the accumulated Pb2+ concentration and the TSCD-PS has a strongest sensitive to Pb2+ at pH = 4.0. The results display that the anodic peak current densities increase with the increasing Pb2+ concentration and they have a good fitting with a second order exponential function of I = -156exp(-1562[Pb2+]) - 260exp(-105 [Pb2+]) + 446 (R2 = 0.99).
Conclusion: The TSCD-PS shows the property to determinate Pb2+ in aqueous solution, which demonstrates that the modified PS is expected to be a promising platform for detecting toxic metal ions.
Keywords: Covalent modification, FT-IR, ions sensor, lead ions detection, porous silicon, TSCD-PS.
Graphical Abstract
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