Construction And Application Of Multifunctional Nanomaterials In Electrohemiluminescence Immunoassay

Electrochemiluminescence immunoassay combines the advantages of the electrochemiluminescence（ECL）and the immunoassay.As a new type of analysis and detection technology,it has the characteristics of strong specificity,high sensitivity,wide linear range,rapid detection and wide use.It has been widely used in many analytical fields,such as environmental analysis,food analysis and drug analysis.In this dissertation,Ag@Au,PAMAM-AuNPs,GO-g-C₃N₄,MWCNTs-AuNPs and were synthesized and used in electrochemiluminescent immunoassay（ECLIA）to establish a sensitive and dual signal amplification electrochemiluminescence immunosensor.Brombuterol（Brom）and water pollutant diclofenac sodium（DCF）were rapidly and sensitively detected.The establishment of this method can provide a new way of detection for small molecule detection.The dissertation includes four chapters:In chapter 1,the paper introduces the research background and significance of the paper.The basic theory and reaction mechanism of electrochemiluminescence immunoassay are described,and the application of multi-functional nanomaterials in electrochemiluminescence immunoassay and sensors is emphatically summarized.In chapter 2,a novel competition-type ECL immunosensor has been developed based on SCNWs-PAMAM-Ag@Au core/shell NPs as substrates,the Brom as analyst and the PAMAM-Au-CdSe QDs as the bioprobes.The nanocomposites such as Ag@Au,SCNWs and PAMAM-Au were characterized by transmission electron microscopy,scanning electron microscopy and ultraviolet spectroscopy.The electrochemical behavior of the immunosensor was measured by cyclic voltammetry（CV）and electrochemical impedance spectroscopy（EIS）.Under the optimized conditions,the linear regression equation of Brom is y=9224-2026 x,linear correlation coefficient R=0.9966,and the minimum detection limit is 0.037 pg m L-1.Therefore,the immunosensor has high sensitivity and wide dynamic response range to detect Brom.In chapter 3,we designed the dual signal amplification strategies by using MWCNTs-AuNPs and GO-g-C₃N₄ nanomaterials to construct competitive-type biosensors for sensitive detection of DCF.The nanocomposite materials such as MWCNTs and GO-g-C₃N₄ were characterized by transmission electron microscopy,scanning electron microscopy,ultraviolet spectroscopy,X ray diffraction（XRD）and infrared spectroscopy（FT-IR）.The electrochemical behavior of the immunosensor was studied by cyclic voltammetry（CV）and electrochemical impedance spectroscopy（EIS）.Under the optimal conditions,the linear regression equation of DCF is IECL = 10144-2403 log（CDCF）,and the linear correlation coefficient R=0.9945,the detection limit is 1.7 pg m L-1.It is obviously lower than the traditional method.The feasibility of the method is further verified by the detection of real samples.In chapter 4,the preparation and characterization of AuNPs@C₆₀,Au@BSA and an electrochemiluminescence immunosensor that can be used to detect enrofloxacin is constructed by using AuNPs@C₆₀ nanocomposite as the substrate of the sensor and the antibody labeled by Au@BSA as a biological probe.The sensor can be used to detect residues in edible animal tissue of enrofloxacin（Enro）and its metabolite ciprofloxacin.