Multiregulation of Aggregation-Induced Emission (AIE) via a Competitive Host–Guest Recognition and α-Amylase Hydrolyzing

The multiregulation of aggregation-induced emission (AIE) that responds to external stimuli to finish multifunctions has become a focus of interest in biodiagnosis. Host–guest- recognition is an efficient strategy to introduce switchable, reversible, and other functional properties into AIE molecules. Herein, an amphiphilic tetraphenylethylene (TPE) derivative TPE-PEG is prepared via the simple amidation reaction and chosen as an AIE-based guest polymer. The aggregated state of TPE-PEG is altered and the fluorescence of TPE-PEG can be turned off in the presence of γ -cyclodextrins ( γ -CDs) due to the formation of host–guest complex between TPE units and γ -CDs. TPE units in the cavities of γ -CDs are released free and an aggregated state of TPE-PEG is restored via the guest competition epistasis of bile acid. Meanwhile, α -amylase can hydrolyze the host molecules of γ -CDs, resulting in an aggregated state of TPE-PEG again and turning the fluorescence on subtly. This reversible multiregulation of fluorescence may meet the multirequirements for the diagnosis in vivo due to the biological nature of α -amylase and bile acid.