An imidazo[1,5-a]pyridines-based ratiometric fluorescent probe for sensing sulfur dioxide derivatives in real samples based on a FRET mechanism

A novel fluorescence resonance energy transfer (FRET)-based ratiometric emission fluorescent probe AT was designed and developed in which the imidazo[1,5-alpha]pyridine was served as a FRET donor and tricyanofuran (TCF) as the FRET acceptor to detect SO32-/HSO3- based on the Michael addition reaction. Probe AT had a high energy transfer efficiency (95%) and a large pseudo-Stokes shift (259 nm) in EtOH/PBS buffer (5/5, v/v). It also possessed good selectivity and quick response to SO32-/HSO3-. There was good linearity between the ratio of fluorescence intensity (F-499/F-645) and the concentrations of SO32-/HSO3- in the ranges of 1.5-7.5 mu M and 9-20 mu M, with calculated detection limits (LOD) of 55 nM. In addition, the probe could also detect the concentrations of SO32-/HSO3- in real samples such as environmental water and sugar, allowing the probe to be used in a variety of applications.

Automated summary

A novel fluorescence resonance energy transfer (FRET)-based ratiometric emission fluorescent probe AT was developed for the detection of SO32-/HSO3-. It showed high energy transfer efficiency, large pseudo-Stokes shift, good selectivity and quick response. The probe also demonstrated its applicability in real samples such as environmental water and sugar.