Selective detection of nitrite ion by an AIE-active tetraphenylethene dye through a reduction step in aqueous media

This paper reports a highly selective nitrite ion receptor based on an AIE-active tetraphenylethene-bearing amino functionality. In water, the receptor has been shown to be selective for nitrite ion (NO2−) over other anions (NO2−, CH3COO−, NO3−, CO32−, S2O32−, SO42−, HSO3−, and Cl−), with pronounced changes in absorption characteristics i.e. red-shift of ∼30 nm. The visual observation of colour change, shift in absorption, and enhancement of emission, clearly show that this receptor is very selective and sensitive to nitrite ions.