Visual detection and removal of mercury ions by a ferrocene derivative

New ferrocene naphthyridine derivatives were successfully synthesized. The di-substituted ferrocene derivative FecDN behaves as a selective visual chemosensor for mercury ions, exhibiting a rapid and clearly visible precipitation with good selectivity (precipitation) and sensitivity (0.01 μM). The interaction of the ferrocene derivatives and metal ions was investigated by ultraviolet–visible spectroscopy (UV–vis), electrochemical methods, 1H NMR, as well as infrared (IR), and energy dispersive X-ray spectroscopy (EDX). The application of FecDN in the detection and removal of mercury ions is very simple, rapid, and intuitive.