Dicyanoisophorone based fluorescent probe for rapid S^2- detection and its applications in water and bioimaging

A novel dicyanoisophorone-based fluorescent probe, IsoDiOH, was successfully designed and synthesized, exhibiting a remarkably large Stokes shift of approximately 156 nm. The molecular structure was unambiguously confirmed through ¹H NMR characterization and high-resolution mass spectrometry, while its photophysical properties were systematically investigated. Notably, IsoDiOH demonstrated exceptional selectivity and sensitivity for S^2- detection, as evidenced by a distinct colorimetric transition from orange to green under ambient light and significant fluorescence quenching following S^2- introduction. The probe exhibited ultrafast recognition kinetics (< 20 s) toward S^2- with a calculated detection limit of 0.31 μM. To validate practical applicability, environmental water sample and live-cell imaging experiments were conducted, revealing that IsoDiOH possesses significant potential for practical applications in environmental monitoring and biological systems.