A ratiometric AIE probe with sequential activation for selective dual detection and imaging of fluoride and hypochlorous acid.

The development of efficient dual-detection systems for fluoride ions (F^-) and hypochlorous acid (HClO) in biological environments represents a significant challenge in analytical chemistry, given their distinct chemical properties and crucial yet contrasting roles in physiological processes. Addressing this challenge, we have engineered a sequentially activated fluorescent probe (SA-S-TBM) that leverages aggregation-induced emission (AIE) characteristics to achieve unprecedented simultaneous detection of both analytes under physiological conditions. The design overcomes traditional limitations through a unique cascade activation mechanism: initial F^--induced desilylation generates a red-emitting SA-S intermediate, which subsequently undergoes HClO-specific oxidation to produce green-fluorescent SA-SO, creating two well-resolved emission peaks (Δλ = 98 nm) that effectively eliminate spectral interference-a critical advancement in dual-analyte detection technology. Remarkably, SA-S-TBM demonstrates exceptional analytical performance with ultrahigh sensitivity (detection limits of 20.3 nM for F^- and 1.72 μM for HClO) and outstanding selectivity against competing biological species. Moreover, with low toxicity and excellent cell permeability, SA-S-TBM successfully visualized intracellular F⁻ and HClO through distinct fluorescence signals, highlighting its strong potential for biological detection and as a tool to explore their roles in pathophysiological processes.