Noncovalent assembly of non-metallic porphyrin on graphene oxide nanosheets and its application for simultaneous determination of Cu2+ and Pb2+ in real water

A newly developed electrochemical sensor for simultaneous detection of Cu2+ and Pb2+ in polluted water using the non-metallic porphyrin functioned graphene oxide (GO) by π-π noncovalent interactions is demonstrated. Introduction of 5,10,15,20-tetra(4-hydroxyphenyl)-21H, 23H-porphine (THPP) on GO nanosheets resulted in enhanced electron transfer due to the high electron mobility of GO and the excellent electron-feeding properties of THPP. Due to the synergistic effect between THPP and GO, the prepared sensors showed remarkable electrocatalytic activity for the reduction of Cu2+ and Pb2+. It exhibited two-segmentinear response over the concentration range from 5 − 300 μM and 300–––900 μM with a detection limit of 1.5 μM for Cu2+ and two-segment corresponding linear range of 5–––250 μM and 250–––900 μM with a detection limit of 1.6 μM for Pb2+. In addition, the proposed sensor has excellent anti-interference ability for some common cations and anions. The technique can be used successfully for simultaneously detection of residual Cu2+ and Pb2+ in real water, thus demonstrating its high utility for conventional sensing applications in real environments.