A turn-on AIE dual-channel fluorescent probe for sensing Cr3+/ClO− and application in cell imaging

A Cr³⁺/ClO⁻-enhanced fluorescent probe, DNS (5-(dimethylamino)-N′-(2-hydroxy-4,6-dimethoxybenzylidene)-naphthalene-1-sulfonyl hydrazide), with aggregation-induced emission (AIE) properties was synthesized using dansylhydrazide and 4,6-dimethoxysalicylaldehyde as starting materials. The probe rapidly and selectively detects Cr³⁺ and ClO⁻ in a solvent system of H₂O/DMSO (2:8). Upon binding with Cr³⁺/ClO⁻, the probe exhibits a significant fluorescence enhancement, with minimal interference from other ions. The detection limits (LOD) were determined to be 5.36 × 10⁻⁷ mol/L for Cr³⁺ and 3.65 × 10⁻⁷ mol/L for ClO⁻. The binding mechanisms of DNS with Cr³⁺/ClO⁻ were investigated through Job’s plot, 1H NMR titration, and mass spectrometry. Furthermore, the probe’s low cytotoxicity and biocompatibility suggest its potential for detecting exogenous Cr³⁺/ClO⁻ and endogenous ClO⁻ in living cells. DNS shows promise for real-time detection and bioimaging applications.