Ratiometric fluorescent probe for biothiol in aqueous medium with fluorescent organic nanoparticles.

A dipodal rhodamine-based mercury complex have been designed and synthesized, for the selective detection of 3-mercaptopropionic acid (MPA). To avoid the poor solubility of rhodamine-based ligand in pure water, the Hg(2+) complex of fluorescent organic nanoparticles (FONs) of ligand have been developed using reprecipitation method and the formation of 1:1 complex has been confirmed with various spectroscopic techniques. The resultant chemosensor can detect MPA in a concentration range of 60 nM-1 μM (in buffered aqueous medium) with detection limit of 60 nM.