Bipolar Electrochemiluminescence Based On Iron Electrode

Electrochemiluminescence is a kind of luminescence phenomenon caused by chemical reaction.It does not need other light sources for light excitation,has no background light interference,and has high detection sensitivity.As a new type of sensor,bipolar electrochemiluminescence sensor has the characteristics of low cost,simple operation,fast response and high sensitivity.There are many researches in the fields of biological analysis,micro/nano scale imaging of single cell/single particle,and the mechanism of electrochemical processes.Diabetes,Parkinson’s disease and other diseases are chronic diseases caused by the lack of corresponding hormones or other biological function damage.The development of simple and sensitive glucose and choline detection strategies is of great significance for the diagnosis and treatment of related diseases.In this paper,Fe was used as a bipolar electrode in an open bipolar ECL device.Hydrogen peroxide was generated by the reaction between the enzyme specificity and its corresponding substrate,which was used as a co reagent of luminol to construct an efficient and sensitive electrochemical biosensor.Since bipolar electrochemiluminescence,rotation is introduced to enhance ECL luminescence intensity through the convection phenomenon generated by rotation,so as to achieve efficient detection and analysis of glucose and choline.Luminol,as a common ECL luminescent,usually emits light only at the anode.Up to now,there is no report that luminol emits light simultaneously in the oxidation and reduction process.We found the ECL emission phenomenon of luminol and L-012 sodium salt.We selected different electrode materials to study the ECL emission behavior of their cathode and anode.Another originality of this work is the successful recording of bipolar ECL emission in an open configuration bipolar electrochemical reaction device.Based on the above ideas,the following two experimental systems were carried out:1.Detection of glucose/choline by wireless rotating bipolar electrochemiluminescenceUnder the combined action of external magnetic field and electric field,the iron wire electrode rotates in a double non-contact mode to produce light emission at the two poles.Using this wireless rotating bipolar electrochemiluminescence device,an ECL biosensor was designed to judge the content of glucose/choline by ECL light intensity.Under physiological p H value,the specific catalytic performance of glucose oxidase(GOD)and choline oxidase(Ch Ox)can selectively react with glucose and choline respectively to catalyze glucose and choline to produce hydrogen peroxide.Hydrogen peroxide,as a co reagent of luminol,catalyzes luminol to produce ECL emission.During the rotation process,the change of ECL intensity can be used to track the movement of iron wire bipolar electrode.The experimental results show that this method can realize the quantitative detection of glucose/choline,and the detection limits are 10.0 μM and 4.0 m M.The method has high sensitivity and accuracy and has a broad application prospect in biological detection fields such as dynamic enzyme detection and immunoassay.2.Enhanced Cathodic Electrochemiluminescence of Luminol on Iron ElectrodesThe electrochemiluminescence behavior of luminol and its derivative L-012 on different electrode materials was studied.Using hydrogen peroxide as a co reaction reagent,strong cathode ECL emission was observed on iron and stainless-steel electrodes.Under the same experimental conditions,compared with other electrode materials(AU,Pt,C),no cathode ECL signal was observed on these electrodes,and the cathode ECL signal on Ni electrode was weak.This indicates that iron and iron containing materials play a key role in improving ECL emission of luminol cathode.Under the optimum experimental conditions,the ECL signal of cathode is comparable to that of anode.This ECL phenomenon that luminol and its derivative L-012 simultaneously produce light emission during oxidation and reduction has not been reported before.It has shown great application potential in the fields of biosensor,bipolar ECL analysis and ECL cell micro imaging.