8-Hydroxyjulolidine-9-carboxaldehyde

8-Hydroxyjulolidine-9-carboxaldehyde (9-Formyl-8-hydroxyjulolidine) serves as a fluorescent probe, highly selective for hydrogen sulfide (S2−) and silicates (SiO32−) . It operates by inhibiting the mechanism of intramolecular charge transfer (ICT), resulting in significant fluorescence enhancement in the presence of weak acid ions. This compound holds potential for fluorescence imaging studies of hydrogen sulfide within living cells.