Study On Paper-based Photoelectrochemical Biosensor Based On ZnO And Hybrid Chain Reaction

Photoelectrochemical sensor is a detection device for analyzing target,based on the photoelectric conversion characteristic of materials by chemical or biological probing recognition.Photoelectrochemical sensor includes sensing identification unit and photoelectric conversion unit,and the selection of photoelectric material and the design of sensor recognition strategy are of extreme importance in the fabrication of sensitive sensor.Benefitting from the separation of the excitation source(light)and de tection signal(photocurrent),the photoelectrochemical sensor possesses reduced background signa ls.It has the advantage of low background signal,high sensitivity,simple instruments,short response time.Therefore photoelectrochemical sensor has received an increasing attention in the field of environmental detection and biological analysis.In this paper,zinc oxide was selected as photoelectric material and hybridization chain reaction was selected as signal amplification strategy.Combined with the laboratory study in paper,paper-based photoelectrochemical biosensor was fabricated,which realized the sensitivity detection of antigen,polysaccharide and protein.Our main research is as follows:(1)Microfluidic paper-based analytical device for photoelectrochemical immunoassay with multibranched hybridization chain reaction and PdAu mimetic enzyme.We enhance the conductivity of the substrate by in-situ growing gold nanoparticles on paper.Zinc oxide sensitized by quantum dots with different sizes was se lected as photoelectric material.A large number of PdAu mimetic enzyme was introduced in our system by multiple hybridization chain reaction,which realized the sensitive detection for carcino embryonic antigen.(2)Ultrasensitive photoelectrochemical biosensing for cell surface N-glycan expression.In this work,the localized surface plasmon resonance,multibranched hybridization chain reaction and GQDs-induced signal amplification strategies were integrated exquisitely and applied sufficiently.In addition,the chemiluminescent emission served as an inner light source to excite photoactive materials.The designed sensor can be used for quick and sensitive detection of cell surface N-glycan expression.(3)Internal light source-driven photoelectrochemical 3D-rGO/cellulose device based on cascade DNA amplification strategy and hemin/G-quadruplex mimic enzyme.We fabricate greeting card-like paper-based sensor with hollow channels.Combined with target analog chain circulation amplification strategy and introd uction of hemin/G-quadruplex,the biosensor based on 3D-rGO/cellulose has a sensitive response to thrombin.