HDBB@ZIF-8 fluorescent nanoprobe with hereditary alcohols selectivity for chemical sensing

A HDBB@ZIF-8 fluorescent probe has been developed by encapsulating the aggregation-induced emission (AIE) molecule 4,4’-(hydrazine-1,2-diylidenebis(methanylylidene)) bis(3-hydroxybenzoic acid) (HDBB) into the nanochannels of zeolitic imidazolate frameworks-8 (ZIF-8) for distinguishing small alcohol solvent molecules. The crystal structure and morphology of ZIF-8 are well maintained after the encapsulation of HDBB molecules. Encapsulation of HDBB into the confined nanospace of ZIF-8 not only triggered new green fluorescent emission but also endowed them with unique carbon chain length-dependent fluorescence intensity for alcohols, which has not been observed in pure HDBB and ZIF-8. This property could be attributed to the alcohol–water sorption selectivity of host ZIF-8. Moreover, a linear relationship is obtained between the fluorescent intensity of these composites and the concentrations of ethanol with a wide linear range, which could be employed as a chemosensor to detect the content of ethanol in the real wine sample.