A novel imidazophenazine-based metallogel act as reversible H2PO4− sensor and rewritable fluorescent display material

•Novel 1H-imidazo[4,5-b]phenazine-based organogelator and sensor.•Metallogel-based reversible H2PO4− sensor could act as H2PO4− test kits.•1H-imidazo[4,5-b]phenazine moiety acts as signal group and binding sites.•High selectivity and sensitivity for H2PO4−.•Metallogel-based rewritable security display materials.

By rationally introduced 1H-imidazo[4,5-b]phenazine moiety into the gelator molecular, a novel organogelator G5 was designed and synthesized. Imidazophenazine moiety could act as fluorescent group as well as binding site. The gelator G5 could form a stable organogel (OG5) accompanied with dramatic aggregation-induced emission enhancement (AIEE) in DMF. The AIEE of OG5 could be quenched by adding Fe3+ into the OG5. Meanwhile, OG5 could form no fluorescence stable metallogel (FeG) with Fe3+. Interestingly, the metallogel (FeG) could reversibly fluorescent “turn-on” sense H2PO4− with high selectivity and sensitivity. The detection limit of FeG for H2PO4− is 1.0 × 10−6 mol L−1, moreover, other ions did not interfere in the sensing process. The H2PO4− sensing mechanism was confirmed based on competitive coordination between gelator, Fe3+ and H2PO4−. The metallogel FeG could act as reversible H2PO4− sensor and convenient H2PO4− test kits. In addition, the FeG film also could act as an rewritable fluorescent display material.

Graphical abstractBy rationally introduced imidazophenazine group into the gelator molecular as fluorescent and binding sites, a novel supramolecular metallogel-based H2PO4− response material has been developed. The supramolecular metallogel could sense H2PO4− with high selectivity and sensitivity in aqueous solution. This metallogel can act as an 'Off-On-Off' fluorimetric sensor and a rewritable fluorescent display material.Download high-res image (128KB)Download full-size image