A novel lysosome targeted fluorophore for H2S sensing: Enhancing the quantitative detection with successive reaction sites

A novel lysosome targeting fluorophore Lyso-Rh-S-DNP was designed with integration of electron withdrawing 2,4-dintrophenyl (DNP) and electron donating salicylaldehyde (S) on rhodamine (Rh) backbone for unusual successive reaction based emission leading to the quantitative detection of H 2 S. The emission intensity was shifted linearly with the introduction of three individual range of H 2 S. The distinguishable fluorescent behavior was ascribed to the sequence of ether (C-O) cleavage and Spiro-lactam ring opening, which was verified using NMR and HR-MS techniques. In addition, the probe expressed fast response (3 min.), high selectivity and remarkably low detection limit (8 nM) towards H 2 S. A series of successful confocal scans in Hela cells and zebra fish showing H 2 S concentration dependent bioimaging (cyan, green and red) further demonstrated the applicability of this fluorophore for predicting cancer in early stages in bio-systems.