A novel ratiometric fluorescent probe for selective detection of bisulfite in living cells

Abstract

A new type of ratiometric fluorescent probe, 8-(diethylamino)-2-methyl-4-oxo-4H-pyrano[2,3-b]chromen-10-ylium tetrafluoroborate (APCT), is reported. A new type of ratiometric fluorescent probe, 8-(diethylamino)-2-methyl-4-oxo-4H-pyrano[2,3-b]chromen-10-ylium tetrafluoroborate (APCT), is reported. This probe can successfully detect bisulfite anions with a detection limit of 6.1 × 10⁻⁷ M based on Michael-type addition reaction in pH = 7.4 Tris buffer solution containing 70% DMSO (v/v). The response time of the probe is approximately 5 min. Upon treating with bisulfite anions, the probe exhibits an obvious blue shift from 560 nm to 510 nm and the fluorescence intensity ratio at 510 nm and 560 nm (I₅₁₀/I₅₆₀) displays a good linear relationship with the concentration of HSO₃⁻ in the range of 20–120 μM. Additionally, the preliminary cell imaging experiments using HeLa cells demonstrate that the probe can be used to detect intracellular bisulfite anions.