Construction And Application Of Controlled Release Electrochemiluminescence Sensor Based On Mesoporous Silica

The continuous discharge of pollution sources leads to the enrichment of environmental estrogen in water,which damages human reproductive system and greatly increases the risk of cervical cancer and prostate cancer,posing a serious threat to ecological security and human health.The detection of various pathogenic biological macromolecules has become an effective means of disease prevention and diagnosis and mortality reduction.Electrochemical luminescence（ECL）sensor,as an accurate,selective,simple and inexpensive detection method,is very suitable for the detection of various pathogenic biological macromolecules.In the ECL sensor,the control release strategy is used to make the detection results faster and more accurate.In controlled release,mesoporous silica has the characteristics of large pore volume,adjustable pore volume,good biocompatibility and easy modification to be selected as the carrier of controlled release.In this paper,we study the sensitive detection of environmental pollutants and tumor markers by using mesoporous silica as the carrier of ECL sensor.The main research content and results of this topic are mainly divided into the following three aspects:1.A novel target molecule response controlled release electrochemiluminescence sensor for sensitive detection of environmental estrogen trenbolone.The continuous discharge of pollution sources leads to the continuous detection of environmental estrogens in various environmental media,and leads to the phenomenon of fish feminity in some areas,which poses a serious threat to environmental health and ecological security.Therefore,rapid detection of trenbolone in the environment is an urgent problem to be solved.A controlled release system based on aminodized mesoporous silica nanoparticles（MSN-NH₂）was developed to prepare a novel electrochemical luminescence sensor for the quantitative detection of environmental estrogen trenbolone.Based on Manganese nanoparticle（Mn NFs）and([Ru（bpy）₃]²⁺),MSN-NH₂was used as carrier to carry tripropylamine（coreactive agent）.The mesopore of MSN-NH₂was blocked by gold nanoparticles modified with trenbolone antibody（Au NPs-Ab）.When the antigen was added,Au NPs-Ab was detached from the surface of MSN-NH₂and TPr A was released from the mesopore through specific binding of antigen and antibody,thus realizing the sensitive detection of trenbolone.Under the optimal experimental conditions,the detection range of the sensor was 10 fg/m L～50 ng/m L,and the detection limit was 4.73 fg/m L.The controlled release immunosensor has a wide detection range and a low detection limit for the detection of environmental estrogen trenbolone.2.Target molecular responsive electrochemiluminescence controlled release immunosensor for sensitive detection of prostate specific antigen.A novel target molecule responsive electrochemiluminescence（ECL）controlled release immunosensor based on aptamer molecular gate was designed to detect prostate antigen（PSA）in a sensitive manner.As a base material,the oxygen-rich cobalt trioxide（Co₃O₄NRs）can promote the formation of oxygen evolution reaction（OER）and the formation of free radicals,thus improving the ECL strength of superoxide radical(O₂^·-)-luminol system in neutral media without other coreactants such as H₂O₂and dissolved O₂.In addition,the biological response release system was controlled by the reaction of the target PSA with aptame-sealed,luminol-loaded mesoporous silica nanoparticles（MSN）to release large amounts of luminol to obtain an electrochemical luminescence signal.Therefore,as the PSA concentration increases,more luminol can be released and the electrochemical luminescence signal was enhanced.The results showed that the electrochemiluminescence signal was log-linear correlated with PSA concentration from 0.1 pg/m L to 100 ng/m L.In addition,ECL has good stability and specificity.The feasibility of ECL sensor applied to PSA detection in real samples was satisfactory.3.Construction of sandwich-type electrochemiluminescence sensor based on Mo₂C@C nanomaterialsA stimulus-responsive electrochemiluminescence sensor based on manganese dioxide（Mn O₂）gated dendritic large-pore mesoporous silica nanoparticles（DLMSN）was constructed for the sensitive detection of glutathione（GSH）.DLMSN were used as containers to encapsulate boron carbon oxynitride quantum dots（BCNO QDs）and manganese dioxide nanosheets obtained by reduction of KMn O₄by 2-（Nmorpholino）ethanesulfonic acid（MES）were used as molecular gates.In the absence of GSH,manganese dioxide nanosheets can effectively block mesoporous pores.However,in the presence of GSH,the reaction occurred between GSH and manganese dioxide nanosheets,which reduced Mn O₂to Mn²⁺,thus opening the mesopore and releasing the loaded BCNO QDs.Therefore,the constructed electrochemiluminescence sensor realized quantitative detection of GSH which showed a low detection limit（0.21μg/m L）and a broad liner range（0.6μg/m L-80μg/m L）.The constructed electrochemiluminescence sensor will have great potential for biological analysis.