Construction And Application Of Anti-protein Contamination Photoelectrochemical Biosensor

Photoelectrochemical（PEC）sensor is a new biological analysis technology that combines photoelectrochemical technology and electrochemical analysis.It not only inherits the advantages of electrochemical biosensors such as simple installation and low cost,but also has the advantages of low background interference and high sensitivity due to the different energy forms of excitation signals and detection signals used.With the in-depth study of PEC technology,photoelectric chemical sensors have been widely used in the detection of biological molecules,which can achieve highly sensitive tracking of biological small molecules,polypeptides,proteins,DNA,and even the dynamics of biological molecules in deep tissues or organs.It has significant scientific significance for accurate and quantitative analysis and detection of biological small molecules,achieving early diagnosis and treatment of various human diseases,or exploring the basic laws of human life systems.However,due to the complex composition of actual biological samples（such as blood,serum,saliva,cells,living organisms,etc.）,when biosensors are applied to actual samples,non-specific biological contamination adsorption phenomena such as proteins,lipids,cells,microorganisms,etc.are prone to occur on the microelectrode surface,preventing the target from reaching the sensing interface and possibly inactivating it,resulting in detection accuracy,selectivity.Due to the significant reduction in sensitivity and reproducibility,it is particularly important to develop biosensors that can inhibit the adsorption of foulants such as proteins,and to construct photoelectric biosensors that can achieve high sensitivity and antifouling in vivo.This paper mainly discusses the following parts:Chapter 1:IntroductionThis chapter systematically introduces the basic principles and applications of photoelectrochemical anti-pollution organisms.The basic principles of photoelectrochemistry and the classification,characteristics and applications of photoelectrochemical active materials are briefly described.The research progress and important applications of photoelectrochemistry are systematically introduced,and the principles and applications of photoelectrochemical biosensors are introduced emphatically.In addition,the basic principles and significance of constructing biological antifouling interface are described in detail,and the material characteristics and application of antifouling interface construction are introduced emphatically.Finally,the research content and research significance of this paper are expounded.Chapter 2:Antifouling photoelectrochemical biosensors based on zwitterionic polymersA zwitterionic polymer-based photoelectrochemical anti-fouling biosensor was designed and constructed for the dynamic detection of kanamycin concentration in the tail vein of mice.A Ti O₂NTs photoelectrode with excellent photoelectrochemical properties was prepared by a two-step anodic oxidation method,and a PDA/SBMA antifouling layer was constructed using polydopamine and zwitterionic polymer SBMA,which has excellent hydrophilicity and electrical neutrality,which can effectively inhibit the non-specific adsorption of proteins.The PEC biosensor constructed after further modification of the aptamer showed good linear response and excellent selectivity,and could be used for the detection of kanamycin.Finally,the microelectrode was applied to the dynamic monitoring of kanamycin in the tail vein of mice,and the concentration of kanamycin in the blood was monitored in real time.Chapter 3:Photoelectrochemical biosensors based on metal-organic frameworks and hydrogel composite antifouling interfacesCommon antifouling coatings usually cause electrode passivation problem,so a metal-organic framework and hydrogel composite antifouling PEC biosensor with good biocompatibility was designed and constructed for the detection of target small molecules in biological samples.First,a Ti O₂ NTs photoelectrode with excellent photoelectrochemical properties was prepared by anodic oxidation,and a MIL-125 metal-organic framework was synthesized in situ,and a good hydrophilic and porous microstructure zwitterionic Z-MOF was constructed by further amino substitution and amphoteric ionization modification.Subsequently,an acrylamide hydrogel with excellent biocompatibility and hydrophilicity was synthesized by photopolymerization on the surface of the electrode,forming a hierarchically sieved antifouling coating Ti O₂ NTs/Z-MOF/Gel.The anti-pollution coating can block the contact of large molecules such as interfering proteins,while allowing the free diffusion of target small molecules and electrons,ensuring the sensitivity of the electrode.Finally,through the specific chelation between dopamine and Ti O₂ NTs,a highly selective and sensitive PEC biosensor was constructed for the detection of dopamine in complex biological samples.