One-step construction of a novel AIE probe based on diaminomaleonitrile and its application in double-detection of hypochlorites and formaldehyde gas

Abstract

As the environmental residues of formaldehyde and hypochlorites are very harmful to human health, a new simple and efficient aggregation-induced emission probe based on diaminomaleonitrile was designed and applied in the independent detection of hypochlorites and formaldehyde. The probe shows high selectivity and anti-interference ability against other potential competitive substances. ClO⁻ promotes the oxidized splitting of CN in the probe, and induces evident color changes visible to the naked eye together with quenched fluorescence. The detection of ClO⁻ by this probe was fast, sensitive, and visible to the naked eye. The detection limit of the probe to ClO⁻ in the range of 0.70–20 μM is 18 nM. Through the condensation mechanism and with amine as the binding site of formaldehyde, the exposed amino group in the probe structure responds sensitively and efficiently to formaldehyde. The probe can effectively monitor 0.50–25 μM formaldehyde in aqueous solutions, with a detection limit as low as 42 nM. A portable solid sensor – a formaldehyde detection plate was built by directly covering the probe on a thin-layer chromatography plate. Thereby, formaldehyde gas can be effectively and sensitively detected, which offers a clue for developing solid-state formaldehyde-detection plates. The high experimental recovery rates prove that this new probe is highly promising in hypochlorite detection in the real water environment.