DB1 and DB2 show rapid response, high selectivity and sensitivity for bisulfite/sulfite anions with significant ratiometric fluorescent signal changes.
The detection limit was determined to be 0.16 μM for DB1 and 0.57 μM for DB2, respectively, which is sufficient to probe the HSO3− concentration in cells.
DB1 and DB2 were successfully applied for bioimaging SO2 derivatives in living cells under one- and two-photon confocal microscopy.