Chromogenic ‘naked eye’ and fluorogenic ‘turn on’ sensor for mercury metal ion using thiophene-based Schiff base

Abstract

2-((3-Methylthiophen-2-yl)methyleneamino)benzenethiol (Probe 1) is selective for Hg²⁺. The binding affinity of Hg²⁺ with Probe 1 was confirmed by DFT and electrochemical behaviour. The limit of detection was 20 μM with 2 : 1 stoichiometry of 1 + Hg²⁺ complex.