Sodium alginate/mesoporous silica composite hydrogel with AIE characteristics for sensitive detection and efficient capture of Fe3+

The development of integrated platform for the simultaneous detection and removal of heavy metal ions remains critical challenge in environmental monitoring. Herein, tetraphenylethylene-modified mesoporous silica nanoparticles (MSN-TPE) were fabricated via Schiff base reaction, and then incorporated into sodium alginate (SA) hydrogel for simultaneous detection and adsorption of Fe 3+ . The as-prepared hydrogel and MSN-TPE probe exhibited strong aggregation-induced emission (AIE) fluorescence, excellent stability against long-term storage, varied pH and temperatures. The hydrogel achieved sensitive and selective fluorescence quenching response to Fe 3+ , with a detection limit as low as 0.460 μM. Thanks to its porous network structure and abundant active sites, the hydrogel also demonstrated significant adsorption capacity for Fe 3+ , with the maximum theoretical adsorption capacity of 383.06 mg/g. Mechanism analysis indicated that Fe 3+ quenched the fluorescence of probe through static quenching, and the adsorption process was mainly driven by the coordination and electrostatic interactions between Fe 3+ and the nitrogen/oxygen functional groups in hydrogel. Combined with simple preparation and excellent anti-interference ability, this dual-functional hydrogel shows broad application prospects in water quality monitoring and heavy metal purification.