Fluorescent Probes With Aggregation-Induced Luminescence Properties For Multicomponent Detection And Immunoassay Sensing

Here we present a fluorogenic multianalyte biosensor via self-assembly of tetraphenylethene（TPE）molecules.The approach was using a new TPE derivative modified with diethylenetriamine（TPDA）,which could specifically react with pyrophosphate（PPi）by hydrogen linkage.Energy simulation analysis indicated that the coupling reaction will lead to intermolecular cross-linking among TPDA molecules and thus turn on aggregated-induced emission（AIE）at 470 nm.When alkaline phosphatase（ALP）was introduced,PPi was hydrolyzed and fluorescence emission was turned off.The proposed system allows sensitive detection of ALP activity in serum(LOD=0.09mU mL^-1)and PPi（LOD=66.7 nM）.For ALP assay,this is the first example using PPi as the substrate with AIE probe,which is advantageous in pH selection（pH 7.4）than conventional approaches（pH 8.0-9.6）.For PPi analysis,this method does not require metal ions,offering better stability with little interference.We further applied the TPDA-PPi complex as fluorogenic substrate for ALP in an immunoassay and proved that the method is much more sensitive(LOD=0.8 ng mL^-1)than traditional immunoassay(LOD=4.0 ng mL^-1).This result indicates that the complex showed great potential in ultrasensitive immunoanalysis for biomedical diagnosis.