Design and application of a water-soluble triphenylamine-based probe for rapid analysis of α-amylase activity

In this study, we designed and synthesized a series of aggregation-induced emission luminogens (AIEgens) with D-π-A structures by regulating the donor (D) and acceptor (A) of electron. Unlike GT01 and GT03, the water solubility of GT02 and GT04 synthesized by coupling galactose to them through α-1,4-glycosidic bonds is significantly improved. To reduce the impact of ultraviolet light on α-amylase activity, GT04 was selected as the research object and further studied its response behavior to α-amylase. Certainly, α-amylase could cleave the glycosidic bond of GT04 to change its water solubility, thereby significantly aggregating GT03 and emitting bright fluorescence. Research results present that the limit of detection (LOD) of the α-amylase activity detection curve constructed based on the structural change of GT04 is 0.1864 U/L, and the limit of quantitation (LOQ) is 0.5647 U/L. This method exhibits high specificity and selectivity, with a detection error not exceeding 5 % even when compared to commercial kits, further demonstrating the high reliability of it. Additionally, the reaction time of GT04 and α-amylase has been reduced to 3 min, significantly shortening the overall testing duration. Research results also tell us that high-quality smoke could increase the activity of salivary α-amylase (sAA) by activating the sympathetic nervous system. Undoubtedly, this method provides an effective rapid testing tool for assessing human sensory experiences and the development of high-quality tobacco through the fluctuation of sAA activity.