An Aggregation-induced Emission Probe Based on Host-Guest Inclusion Composed of the Tetraphenylethylene Motif and γ-Cyclodextrin for the Detection of α-Amylase

alpha-Amylase, an essential biomarker in pancreas related diseases and perform a major role in carbohydrates metabolism. Hence, monitoring the dynamic changes of alpha-amylase is crucial for better clinical diagnosis of diseases. However, the existing methods are suffered from low sensitivity, time consumption and indirect assay with aid of tool enzyme or inhibitor of competitive substrates, the rapid and non-destructive sensing of alpha-amylase in biological samples was highly desired. In this work, a very simple tetraphenylethylene motif and gamma-cyclodextrin based supramolecular fluometric sensing system was firstly established. This system has no emission signal in aqueous media for the freely rotation of phenyl rings in the cavity of gamma-cyclodextrin, but the AIE residues can be released in to water after the alpha-amylase hydrolysing gamma-cyclodextrin, then turn on the fluorescence. In this system, the detection limit is calculated to be 0.007 U mL(-1) in MES buffer with a linear range of 0-0.35 U mL(-1), having excellent selectivity to alpha-amylase compared to other proteins. At last, our probe can be applied to the quantitative analysis of alpha-amylase in human serum, showing potential in point of care testing.