A portable strategy for the electrochemical determination of toxic metal ions based on PANI/Ag-ZIF-8 hybrid materials

Heavy metal ions (HMIs) pose a great threat to human health because of their irreversible detrimental effects, thus the fabrication of a convenient sensing platform that is capable of tracing HMIs with high accuracy remains a major challenge. Herein, a portable strategy for the fabrication of electrochemical sensor was described in which Ag-ZIF-8 and polyaniline (PANI) were combined and dropwise to glassy carbon electrode (GCE) for the recognition of Pb 2+ and Cu 2+ by DPSV. The structures and properties of the proposed working electrode (PANI/Ag-ZIF-8/GCE) were studied by TEM, SEM, FT-IR, XRD, CV and DPSV. Additionally, the results revealed that the designed sensing platform of the PANI/Ag-ZIF-8/GCE displayed excellent electrochemical performance for the simultaneous and individual tracing of HMIs including (Pb 2+ and Cu 2+ ) with satisfactory sensitivity and selectivity due to the excellent conductivity of PANI and large surface areas with abundant active sites on Ag-ZIF-8. The LODs for individual recognition of Pb 2+ and Cu 2+ were 0.003 μM and 0.006 μM, respectively. The LODs of simultaneous tracing of Pb 2+ and Cu 2+ were 0.004 μM and 0.008 μM, respectively. Moreover, real sample analysis of tap water and the Songhua River indicated good results with higher reliability for the detection of target HMIs, which may be beneficial for the fabrication of MOF-based probes by a simple strategy for the detection of HMIs to safeguard people’s lives and health.