Development of a highly selective voltammetric sensor for nanomolar detection of mercury ions using glassy carbon electrode modified with a novel ion imprinted polymeric nanobeads and multi-wall carbon nanotubes

This work reports a voltammetric sensor for selective recognition and sensitive determination of mercury ions using glassy carbon (GC) electrode modified with a novel ion imprinted polymeric nanobeads (IIP) and multi-wall carbon nanotubes (MWCNTs). The ion imprinted polymers were prepared by dissolving the certain amount of mercury chloride and 5,10,15,20-tetrakis(3-hydroxyphenyl) porphyrin, in the presence of methacrylic acid and ethyleneglycol-dimethacrylate, using 2,2-azobisisobutyronitrile as initiator. The differential pulse anodic stripping voltammetric technique was employed to investigate the performance of the GC–IIP–MWCNTs modified electrode for determination of hazardous mercury ions. The designed modified electrode was shown a linear response in the range of 1 × 10−8–7.0 × 10−4 M of Hg2+ ion with a detection limit of 5.0 nM and sensitivity 4483.3 nA μM−1. It was found that the peak currents of the modified electrode for Hg2+ ions were at maximum value in acetate buffer. The preconcentration potential and accumulation time were optimized to be −1.0 V and 100 s, respectively.