Construction Of A Novel Anti-Fouling ECL Biosensor And Its Application In The Detection Of Tumor-Related Nucleic Acid

In recent years,the incidence rate and mortality of cancer have been rising,which seriously threatens people’s health.Therefore,there is an urgent need to develop accurate and rapid cancer early diagnosis methods to achieve early treatment of cancer.Due to the low abundance of cancer biomarkers in the early stages of cancer,conventional methods are difficult to analyze and detect.Therefore,this paper uses highly conductive functional nanomaterials and anti pollution materials to modify the electrode,combined with the signal amplification strategy,constructed two kinds of anti pollution hydrogel based electrochemiluminescence biosensors,and realized the sensitive analysis and detection of p53DNA and mi RNA-21 nucleic acids.The specific scheme is as follows::1.An anti pollution electrochemiluminescence biosensor based on bovine serum albumin（BSA）hydrogel and exoenzyme exo III mediated nucleic acid cycle signal amplification strategy was constructed.Ti₃C₂T_x-NH₄has a large surface area and high metal conductivity,and is cross-linked with BSA to improve the conductivity of the sensing interface.Due to the electric neutrality and good hydrophilicity of BSA hydrogel,the sensing interface shows excellent anti pollution performance.The cyclic amplification strategy based on exoⅢand DNA hybridization chain reaction significantly amplified the electrochemiluminescence signal and improved the detection sensitivity of p53.The linear range of the biosensor is 1 f M-1 n M,and the detection limit is 0.26 f M.More importantly,when the sensor is used to detect p53DNA in real samples such as serum,it shows good selectivity.Therefore,this unique antifouling sensor is expected to be applied in clinical diagnosis and pathological analysis of complex biological systems.2.A sensitive anti pollution electrochemiluminescence biosensor based on polyvinylalcohol（PVA）/polyacrylamide（PAAm）hydrogel and catalytic hairpin reaction mediated nucleic acid cycle signal amplification strategy was constructed.In order to improve the conductivity of the prepared hydrogel,carboxyl modified carbon nanotubes（CNT-COOH）with good conductivity were crosslinked with PVA/PAAm,which improved the conductivity of the modified interface.Moreover,the introduction of CNT-COOH also provided functional groups for the introduction of probes,enabling DNA to be modified to the hydrogel surface through the amide bond.The electroneutrality and good hydrophilicity of PVA/PAAm hydrogel endow the sensing interface with excellent anti pollution performance.Through the target induced catalytic hairpin amplification reaction,the electrochemiluminescence signal is significantly amplified,effectively improving the sensitivity of the target mi RNA-21detection.The linear range of the biosensor is 10 f M-10 n M,and the detection limit is4.3 f M.In addition,it also exhibits satisfactory selectivity and stability in the detection of human serum samples and cell lysates,indicating its great potential in biomolecular detection and disease diagnosis.