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 x 10(-8)-7.0 x 10(-4) M of Hg2+ ion with a detection limit of 5.0 nM and sensitivity 4483.3 nA mu M-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. (C) 2013 Elsevier B.V. All rights reserved.