Electrochemiluminescence DNA Sensor Based On Luminol Functionalized Polymer/MWCNTs

In view of the increasing awareness of disease prevention,it is urgent to effectively diagnose the occurrence of various diseases.Electrochemiluminescence analysis technology brings potential possibility to the early diagnosis of human diseases in medicine.This method has the characteristics of high sensitivity,wide linear range,low detection limit and fast analysis speed.Luminol,as a commonly used electrochemiluminescence（ECL）reagent,has attracted extensive attention in the field of ECL.In this paper,two luminescent functional nano materials were prepared by chemical oxidation synthesis method.Using the enhancement and catalysis of H₂O₂,Ferrocene（Fc）and gold nanoparticles（AuNPs）on luminol electrochemiluminescence signal,H₂O₂,Ferrocene（Fc）and Ferrocene group@gold nanoparticles were introduced into the constructed electrochemiluminescence DNA biosensor（Fc@AuNPs）,a highly sensitive ECL DNA biosensor for detecting pathogens was constructed.The details are as follows:1.P（ANi-Lu）/MWCNTs were prepared by chemical oxidation synthesis,the nanocomposites were studied and characterized by UV Vis,TEM,XRD,MFS and ECL.The results showed that P（ANi-Lu）/MWCNTs nanocomposites with stable and excellent electrochemiluminescence properties were successfully synthesized.Taking the nanocomposites as the sensing nano interface and using ferrocene（Fc）and H₂O₂,the ECL signal of luminol is significantly improved,a sensitive and stable electrochemiluminescence biosensor was designed.It is used to detect Mycobacterium tuberculosis DNA in two systems with and without H₂O₂.When H₂O₂was present,it is found that the biosensor showed a good linear relationship in the concentration range from1.0×10^-16～1.0×10^-7mol·L^-1,and the detection limit was 6.8×10^-16mol·L^-1.When H₂O₂was absence,the linear range from 1.0×10^-14～1.0×10^-7mol·L^-1,and the detection limit was 8.85×10^-15mol·L^-1.2.Based on the work in Chapter 1,P（ANi-Lu）/MWCNTs nanocomposites were used as the nano interface of DNA sensor.At the same time,one end labeling was prepared Fc@AuNPs a functional probe and a signal probe with only one end connected to a separate Fc.take Fc@AuNPs and Fc alone were used as sensitizers of DNA sensors to compare their performance.Using these two probes to catalyze luminol,two ECL DNA sensors for detecting pathogens were constructed and applied to the detection of mycoplasma pneumonia DNA.The linear concentration range of ECL DNA sensor based on Fc-DNA/t DNA/c DNA/GA/P（ANi-Lu）/MWCNTs was 1.0×10^-14～1.0×10^-7mol·L^-1,and the detection limit was 9.71×10^-15mol·L^-1.Be based on Fc@AuNPs The linear concentration range of the ECL DNA sensor of Fc@AuNPs DNA-t DNA/c DNA/GA/P（ANi-Lu）/MWCNTs was 1.0×10^-16～1.0×10^-7mol·L^-1,and the detection limit was9.54×10^-17mol·L^-1.3.P（ANi-Lu）/MWCNTs/AuNPs were synthesized by chemical oxidation.The nanocomposites were studied and characterized by UV-Vis,TEM,XRD,MFS and ECL.The results showed that poly（aniline-luminol）/MWCNTs/AuNPs nanocomposites with excellent properties were successfully synthesized.Using the nanocomposites as the sensing nano-interface,a molecular beacon electrochemiluminescence DNA sensor was constructed.The sensor was applied to detect DNA of Staphylococcus aureus.Through experiments,it is found that the biosensor showed a good linear relationship in the concentration range from 1.0×10^-15～1.0×10^-8mol·L^-1,and the detection limit was8.77×10^-16mol·L^-1.