Functionalized graphene oxide-based carbon paste electrode for potentiometric detection of copper ion(II)

摘要

For the first time, a novel copper ion(II) carbon paste electrode (CPE) based on high-density carboxyl functionalized graphene oxide (GO) is reported. A new hybrid material, 2-amino-5-mercapto-1,3,4-thiiodiazole grafted onto nanoscale graphene oxide (AMT-g-NGO), was introduced as a neutral carrier. The electrode exhibits an excellent Nernstian response to copper ion(II) ranging from 1.0 ?— 10a?’7 M to 1.0 ?— 10a?’1 M with a slope of 26.2 mV deca?’1. Meanwhile, the proposed electrode shows fairly good selectivity and a long life time (2 months). Moreover, the excellent performance on low detection limit (4.0 ?— 10a?’8 M), wide applicable pH range (3.0a€“7.0) and fast response time (15 s), reveal the superiority of the electrode. The response mechanism of the electrode was investigated using AC impedance technique and UV-vis spectroscopy. The sensor can be used as indicator electrode for potentiometric titration of Cu2+ ion with EDTA and successfully applied to the determination of Cu2+ ion in different real samples.