Construction Of Noval Antifouling Electrochemical Biosensors And Applications In Detection Of Biomarker

With the development of human society,the average life expectancy is gradually increasing,people’s demand for health is gradually increasing,and the health industry is also gradually developing.However,cancer and other diseases are also increasing the threat to human life and health year by year.Since 1975,the incidence of cancer has been increasing year by year,and the emergence of such diseases shows a trend of younger people.In recent years,although the diagnosis and treatment technology of cancer and other diseases has made great progress,tumor markers are a class of important biomarkers,which can be used for the diagnosis of cancer and other diseases.However,in the early stage of many diseases,the concentration of biomarkers in the body is very low in the blood and body fluids,and because the blood and body fluids contain many other components,the analysis of such biomarkers needs to overcome the interference of complex environment.Therefore,it is very important to develop detection methods with high sensitivity,high specificity and excellent performance that can resist the interference of complex components for the early diagnosis of cancer and other major diseases.Electrochemical biosensors have many advantages,such as high sensitivity,good specificity,low analysis cost,fast response,etc,and can analyze biomarkers at low concentrations in the early stage of disease.However,in a complex environment,interferers such as unrelated proteins,due to electrostatic adsorption and hydrophobicity,are easy to combine with the sensor interface,which will hinder electron transfer and even affect the identification of the biomolecules to be measured.Based on this,this paper designed and synthesized three to resist non-specific adsorption material of resistance to pollution,and in combination with other functional materials,modified electrodes,jointly build a new antifouling electrochemical sensor,realized the decatation of tumor cell MCF-7 cell,glutathione（GSH）and prostate specific antigen（PSA）,the specific plan is as follows:1.In this paper,a self-powered biosensor based on enzyme fuel cell is proposed.The self-powered biosensor based on enzyme fuel cell has attracted much attention because of its unique characteristics,which do not need additional power during the whole detection process,which makes them simple,fast,low cost,anti-interference and easy to use.Self-powered electrochemical biosensors utilize a biofuel cell as both a power source and a biosensor,which simplifies the biosensor system because it eliminates the need for a voltage regulator,the power of the voltage regulator and the power of the signaling device.Herein,we have developed an ultra-sensitive self-powered biosensor based on enzyme biofuel cells for the detection of MCF-7 cells.The biological anode is composed of conductive supramolecular polymer hydrogel,gold nanoparticles,glucose oxidase and MCF-7 aptamer,and the biological cathode is composed of polydopamine,gold nanoparticles and laccase.The two electrodes form a single-chamber self-powered sensor in a buffer solution containing glucose.When MCF-7 cells were captured by anode through aptamer,the significant steric and electrostatic repulsion effectively prevented the electron transfer between anode and cathode surface,which reduced the open-circuit voltage of the sensor,thus realizing quantitative detection of MCF-7 cells.2.In this paper,an antifouling hydrogel based on denaturation BSA protein was presented.A novel antifouling electrochemiluminescence（ECL）hydrogel was prepared by modifying BSA protein as substrate.The protein BSA has 581 a mino acids and is rich in groups.Due to its folded structure,many of the inter nal groups cannot be exposed to play a role.Urea concentration of 6M can be used to uncoil the protein to form a branched polypeptide,and the exposed a mino group is combined with Tris（4,4-dicarboxylbipyridine）ruthenium chloride with carboxyl group.As a dehydrating agent,ethanol reduces the distance betw een the freed proteins and facilitates the action of the crosslinking agent glutara ldehyde,forming a new antifouling electrochemiluminescence gel.The gel has g ood hydrophilic and antifouling effects,stable electrical grade performance,and good electrochemiluminescence signal strength and stability.The constructed elec trode was used to detect GSH with a linear range of 100 μM to 1000 μM and a detection limit of 36.4 μM.The results are stable and reliable,which proves that the hydrogel can be used in the construction of other types of sensors an d other antifouling applications.3.Herein,an electrochemiluminescence biosensor based on Metal-organic framework combined with other materials was developed for the detection of prostate specific antigen（PSA）.3,4,9,10-perylene tetracarboxylic acid（PTCA）is a class of planar organic molecules with desirable optical properties.PTCA has good luminescence performance,but due to its own characteristics,it is prone to aggregation induced quenching（ACQ）,resulting in the reduction of its luminescence intensity.PTCA and metal materials to prepare MOFs can overcome their own aggregation induced quenching.MOFs have a large specific surface area,but their own electrical conductivity is poor.Combined with gold nanoparticles,MOFs are used to improve electrical conductivity and provide more binding sites.Antifouling multifunctional peptide,containing anchor sequence（CPPPP）,antifouling sequence（DKDK）,PSA cleavage sequence（HSSKLQK）,terminal labeled with signal quenching molecule ferrocene（Fc）.An electrochemiluminescence sensor based on MOFs and antifouling multifunctional peptides was designed.It can resist the interference of various proteins in blood.The detection linear range is 1 pg/ mL to10ng/mL,and the limit of detection is 0.46 pg/mL.