Rhodamine based organic nanoparticles for sensing of Fe3+ with high selectivity in aqueous medium: application to iron supplement analysis

Abstract

A rhodamine-based “ON–OFF” fluorescent probe was designed on the bases of modulation in structure between spirocyclic (non-fluorescent) and ring-open (fluorescent) forms of rhodamine dye. The sensing behavior toward metal ions was investigated with fluorescence spectroscopy. The dye has been processed intonanoaggregates throughreprecipitationmethod.NanoaggregatesN1 show highsensitivity andselectivity toward Fe3+ in aqueous medium with detection limit of 9.2 nM, whereas other ions including Li+, Na+, K+, Mg2+, Ca2+, Sr2+, Ba2+, Cr3+, Mn2+, Co2+, Cu2+, Zn2+, Ag+, Cd2+, Pb2+, Hg2+ and Cs+ showed no such spectral change, which constituted a Fe3+ selective fluorescent chemosensor. Further, the practical utility of sensor has been evaluated for analysis of Fe3+ content in iron supplement tablets available in local market.