A near-infrared (NIR) fluorescent turn-on probe for sulfite anions was developed. This probe uses naphthofluorescein as the NIR fluorophore and two levulinate groups as the reaction sites, and shows rapid response, high selectivity and sensitivity for sulfite anions with significant dual colorimetric and NIR fluorescence turn-on signal changes in DMSO-PBS buffer solution. The NIR fluorescence intensity at 695 nm (excited at 620 nm) increases linearly with sulfite concentration in a range of 0–300 μM and the detection limit was determined to b...
