Electrochemiluminescence Biosensor Based On Tetraphenylethylene Derivatives

Since Academician Benzhong Tang discovered the Aggregation-Induced Emission（AIE）phenomenon in 2001,the application of AIE materials has become a hot spot in many disciplines.Due to the characteristic of"the more concentrated the more luminous"of AIE materials,the problem of low luminous efficiency of the most common aggregated luminescent materials in practical applications has been solved,laying a theoretical foundation for the new application of organic light-emitting bodies.Electrochemiluminescence（also called electrogenerated chemiluminescence,ECL）is considered to be a new and effective method for the determination of biomolecules because of its simple operation,high sensitivity,and strong controllability.In this paper,electrochemiluminescence analysis technology and AIE materials are combined to construct an electrochemiluminescence biosensor.The sensor has the advantages of no background signal,high signal-to-noise ratio,good biocompatibility,low preparation cost,etc.,realizes rapid and sensitive detection of disease markers,and provides new ideas and methods for the field of bioanalysis and clinical diagnosis.This article is divided into the following sections:（1）For the first time,the ECL behavior caused by the accumulation of phosphate-functionalized tetraphenylethylene（TPE）on the surface of the electrode was studied,and it was used for the detection of alkaline phosphatase（ALP）activity in aqueous solution.By using triethylamine（TEA）as a co-reactant,the emitter TPE-pho with AIE properties exhibits strong anodic aggregation electrochemiluminescence.In the presence of ALP,the phosphate group on TPE-pho is dissociated and removed from the original conjugated structure through an enzymatic reaction,resulting in weakening of the ECL signal.The new luminescent material used in the ECL sensor has high selectivity and sensitivity to ALP,the lowest detection limit in Tris-HCl buffer is 0.037 U/L,and the linear quantitative range is 0.1-6.0 U/L.This method also tried to detect the ALP content in human serum and cancer cells,with a detection range of 1.0-6.0 U/L,which successfully proved its potential for clinical detection of ALP levels in serum and cancer cells.（2）Combining metal organic framework and metal nanomaterials,a sandwich-type ECL signal double-enhanced electrochemiluminescence biosensor was designed and constructed for sensitive detection of carcinoembryonic antigen CEA.Using 1,1,2,2-tetra（4-carboxylphenyl）ethylene（H₄TCPE）as the carboxylic acid ligand,through the coordination with the metal atom Zr,the wool spherical Zr-based MOFs with three-dimensional structure were successfully prepared.Due to the rigid structure of MOFs,the mechanism of restricted intramolecular motion is enhanced,and the luminescence of Zr-TCPE is further enhanced,and by using its electrocatalytic performance,a large number of reducing free radicals are generated in the solution.When another gold nanocluster（Au NCs）with orange-yellow fluorescence emission is loaded on MOFs,a large number of free radicals make it easier for Au NCs to reach the excited state and release energy to generate ECL emission.Therefore,under the combined action of the two,the double amplification of the luminous signal is realized.This detection method is more sensitive to the detection of CEA,and the detection limit is 1.15 pg/m L in the concentration range of 0.001-50 ng/m L.