Amphiphilic porphyrin film on glass as a simple and selective solid-state chemosensor for aqueous Hg2+

Deposition of amphiphilic porphyrin derivatives occurs spontaneously on silanised glass surfaces, in a controlled fashion. The resulting porphyrin films show appreciable fluorescence emission. This emission can be effectively quenched by immersion of the slides into a diluted solution of Hg2+ (μM concentration). The initial intensity can be restored by washings with a solution of N,N,N′,N′-tetrakis(2-pyridilmethyl)ethylenediammine with no loss of efficiency. A remarkable selectivity is featured toward the detection of Hg2+ over Cu2+, Cd2+, Pb2+ and Zn2+ counterparts. This protocol can be extended to a flow-through apparatus. The presented results are of importance for the achievement of a solid-state chemosensor for mercuric ions, at micromolar concentration, in water.