Development of an ultrasensitive Ru(II) complex-based fluorescent probe with phenothiazine unit for selective detection HOCl and its application in water samples

A near-infrared probe Ru-1 with a phenothiazine derivative moiety as a responsive unit was designed to sensitively and selectively recognize HOCl in pure PBS solution. Upon addition of HOCl to a PBS solution of Ru-1, S-atom of the phenothiazine unit oxidized to sulfoxide, accompanied with a marked fluorescence enhancement about 60 fold at 635 nm. Probe Ru-1 displayed excellent water-solubility (PBS solution), low detection limit (4.4 nM), long fluorescence lifetime (354.36 ns) and large Stokes shift (175 nm). The experiments of its quantitative detection HOCl in water samples implied the probe Ru-1 possessed potential application in the environment.

Automated summary

The Ru-1 probe was designed to sensitively and selectively recognize HOCl in PBS solution, showing excellent water-solubility, low detection limit, long fluorescence lifetime, and large Stokes shift. Quantitative detection experiments in water samples indicated its potential application in the environment.