Mannich Reaction Based Aggregation-induced Emission for Fluorescent Sensitive Detection of Formaldehyde

Formaldehyde is a kind of colorless and odorless carcinogen that can cause many diseases. It is very necessary for the simple and sensitive detection method of formaldehyde in environmental monitoring, toxicological assessment, clinical diagnosis and medical care. Herein, a new fluorescence detection method was developed based on the aggregation -induced emission (AIE) effect for aqueous formaldehyde. An AIE probe of tetra(4- hydroxyphenyl) ethylene (TPE-4OH) was synthesized, which could react with formaldehyde by a Mannich reaction in the presence of 1,2,4,5-benzenetetramine tetrahydrochloride (BTA), causing an obvious enhancement of fluorescence of TPE-4OH. Due to the fluorescence enhancement of TPE-4OH related to the Mannich reaction and the concentration of formaldehyde, the detection of formaldehyde in the aqueous solution could be realized by measuring the fluorescence intensity of TPE-4OH. By optimizing the conditions of reactant concentration, solution pH value and reaction time, the linear range of detection of formaldehyde was from 1.0 mu mol/L to 2000 mu mol/L, and the detection limit (LOD) was 1.0 mu mol/L. The results showed that this method had the potential in sensing/ diagnosis applications of formaldehyde.