Eco‐friendly Sensors Developed by Herbal Based Silver Nanoparticles for Electrochemical Detection of Mercury (II) Ion

In our study, the single‐use & eco‐friendly electrochemical sensor platform based on herbal silver nanoparticles (AgNPs) was developed for detection of mercury (II) ion (Hg2+). For this purpose, the surface of pencil graphite electrode (PGE) was modified with AgNPs and folic acid (FA), respectively. The concentrations of AgNPs and FA were firstly optimized by differential pulse voltammetry (DPV) to obtain an effective surface modification of PGE. Each step at the surface modification process was characterized by using cyclic voltammetry (CV) and electrochemical impedence spectroscopy (EIS). The limit of detection (LOD) for Hg2+ was estimated and found to be 8.43 μM by CV technique. The sensor presented an excellent selectivity for Hg2+ against to other heavy metal ions such as Ca2+, Cd2+, Cr3+, Cu2+, Mg2+, Ni2+, Pb2+, Zn2+, Co2+ and Mn2+. Moreover, a rapid, selective and sensitive detection of Hg2+ was successfully performed in the samples of tap water within 1 min.