Carbon nanotubes/poly(1,2-diaminobenzene) nanoporous composite film electrode prepared by multipulse potentiostatic electropolymerisation and its application to determination of trace heavy metal ions

A novel method for the fabrication of carbon nanotubes/poly(1,2-diaminobenzene) nanoporous composite based electrode was proposed. By multipulse potentiostatic electropolymerization, the multi-walled carbon nanotubes (MWNTs) and poly(1,2-diaminobenzene) were deposited simultaneously on the electrode surface. Compared with the composite prepared by the traditional potentiodynamic method, the composite synthesized by multipulse potentiostatic method has a unique nanoporous structure, exhibits excellent conductivity and better environmental stability. The surface of the resulting electrode was characterized with scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The nanoporous composite film modified glassy carbon electrode was also used Successfully for the simultaneously voltammetric determination of trace level of Cd2+ and Cu2+ at first-time. Under the optimal conditions, the determination limits of 0.25 and 0.33 ppb for Cd2+ and Cu2+ were obtained, respectively The calibration graphs were linear in the concentration range of 5-100 ppb. The electrode system provides an excellent platform for ultra sensitive electrochemical sensors for chemical and biological sensing.