Construction Of Digital Electrochemiluminescence Sensor Based On Bipolar Electrode

In biomedical research,traditional methods study the life activities of considerable molecules/particles within a specific time frame.In recent years,scientific researchers have devoted themselves to studying the behavior of individual molecule/particle.In the process of detecting single molecule/particle,electrochemical detection methods are widely used to explore the basic properties of single molecule/single particle due to their simplicity and convenience,fast detection signals,high sensitivity,and easy portability.Although,so far,single molecule electrochemical detection technology has developed rapidly and gradually approaching maturity.However,there are huge challenges in signal output analysis.Single signal fluctuation is obvious.The detection requirements cannot be achieved by conventional analysis methods,and the low sensitivity of conventional analytical methods limit their practical applications.Therefore,the quantitative analysis of single molecule is imminent.Among them,the combination of digital analysis method has promoted the development of single molecule quantitative methods.However,with this method,cumbersome procedures and measurement procedures make the actual operation time-consuming and laborious.Electrochemiluminescence technology(ECL)has the advantages of direct imaging of ECL signals and high sensitivity.When detecting target,if electrochemiluminescence technology could be used,multiple signals could be output at the same time.Greatly save manpower and time costs.Based on this,this article mainly used electrochemiluminescence technology,and quantitative method of digital analysis was combined to construct a highly sensitive digital electrochemiluminescence biosensor.The main work are as follows:(1)An ultrasensitive electrochemiluminescence(ECL)biosensor based on closed bipolar electrode(BPE)was constructed for the detection of alkaline phosphatase(ALP).The enzyme-induced metallization(EIM)was used as a signal amplification strategy,which could realize single molecule detection based on laboratory development.Au nanoparticles(NPs)were electrodeposited on the cathode surface of ITO electrode to improve the stability and sensitivity of the signal.Compared with the previous BPE-ECL biosensors,this method has high sensitivity,strong specificity,and detection limit as low as 3.7 a M.In addition,it has been further applied to the detection of ALP in different types of cells,and successfully achieved the detection of ALP in single liver cancer cell.(2)A number of ALP molecules and antibodies(p Ab)were successfully modified on the surface of fluorescent magnetic nanospheres(FMNs),which was acted as both signal recognition probe and capture probe.Based on the signal amplification strategy of enzyme catalysis,single particle virus was successfully detected.Combined with digital analysis,a highly sensitive digital ECL biosensor was constructed.This method has high sensitivity and strong specificity,which has promoted the development of single molecule electrochemistry.