A naked-eye visible aluminium (III)-based complex fluorescence sensor for sensitive detection of mesotrione

Mesotrione, which is a kind of herbicide to control broad-leaved weeds, has been increasingly used due to its excellent selectivity, rapid process and low toxicity. However, the excessive application of mesotrione have led to widespread contamination. Herein, a turn-on competitive coordination-based fluorescent probe, 2-hydroxy-1-(9-purin)-methylidenehydrazinenaphthalene (HPM), has been successfully synthesized. HPM could effectively detect Al³⁺ in CH₃OH/HEPES (1/9, v/v) with low limit of detection (LOD) being 0.2 µM via coordination. HPM also exhibited excellent imaging capabilities for Al³⁺ in living cells with low cytotoxicity. On the basis of the competitive coordination of HPM with Al³⁺, the [HPM-Al³⁺] complex could also serve as a potential fluorescence sensor for detecting mesotrione with the LOD of 0.2 µM. Furthermore, [HPM-Al³⁺] complex was applied for the detection of mesotrione in real samples and test paper. Finally, the mechanism of [HPM-Al³⁺] for sensing mesotrione was investigated deeply as well. This work designed a new convenient method for on-site detection of mesotrione without the large-scale equipment or complicated pre-treatment.