Fluorescence detection of α-amylase based on a host-guest complex between a pyrene-derived amphiphile and...

A fluorescence detection platform for α-amylase was developed by exploiting the host-guest inclusion complex formed between γ-cyclodextrin (γ-CD) and a pyrene-functionalized amphiphile (P10CG). Spectroscopic analysis revealed that the pyrene moiety was encapsulated within the γ-CD cavity in a 2:2 stoichiometric ratio, inducing characteristic excimer fluorescence. Upon enzymatic hydrolysis of γ-CD by α-amylase, the subsequent release of P10CG led to a marked decrease in excimer emission intensity. A quantitative linear relationship (R² > 0.99) was observed between the monomer-to-excimer intensity ratio and α-amylase concentrations ranging from 1 to 5 U/mL, with a calculated detection limit of 0.135 U/mL (S/N = 3). The γ-CD/P10CG supramolecular system demonstrated satisfactory sensitivity and selectivity for α-amylase in both buffer solutions and diluted serum matrices, thus providing a potential sensing system for α-amylase in complex biological systems.