Preparation Of Au-Pt Nanowire-Composites And The Application In Electrochemical Detection Of CEA

Immunoassay is an important analytical method, it utilize the specific reaction between the antibody and antigen to selectively recognize and determine the analyte containing the antigen or antibody. The method is of a high degree of specificity and selectivity. Electrochemical immunosensor is defined as a detection device combining immunoassay technology and electrochemical sensing technology, which incorporates a living organism from living systems like antibodies or enzymes, and transforms the immune recognition into electronic signals. Due to its superior performance such as high selectivity and specificity, electrochemical immunosensor has been widely applied into the field of clinical, biopharmaceutical, environmental and so on. Nanomaterial with large surface area, high catalytic property and good biological compatibility, has been widely used in sensor fabrication in recent decades. It can be used as the modified materials on surface of electrode or offer an efficient platform for antibody immobilization during biosensor fabrication, and it can improve the sensitivity, detection limit and range of the biosensor. The application of nanomaterials in biosensor has opened a new horizon for biosensor fabrication. In the paper, a novel, label-free and inherent electroactive redox biosensor based on the nanocomposites is developed for carcinoembryonic antigen (CEA) detection. Our study demonstrates that the proposed immunosensor has been used to determine CEA successfully, providing a new research method for diagnosis and treatment of lung cancer and other related disease. The major contributions are as follows:1. First, ultrathin Pt nanowires (PtNWs) are prepared by hydrothermal synthesis and successfully decorated to the surface of the thionine/graphene composites (THI/rGO). As-prepared PtNWs/THI/rGO composites are new type of nanocomposites, and a novel lable-free electrochemical immunosensor based on PtNWs/THI/rGO composites is produced for the CEA detection.2. Second, Ultrathin Au-Pt nanowires (AuPtNWs) are prepared by hydrothermal synthesis and successfully decorated to the surface of the thionine/graphene composites (THI/rGO). As-prepared AuPtNWs/THI/rGO composites is a new type of nanocomposites, with its optical properties and morphology characterized.3. Last, an electrochemical immunosensor based on AuPtNWs/THI/rGO composites is used for the detection of CEA. It establish the linear relationship between the peak current and the concentration of CEA for the determination of CEA, because the specific reaction between antibody and antigen forms a insulation layer which hinders the transport of electron. The experiment results turn out to be satisfying, when the prepared immunosensor is used in diluted blood samples. Moreover, the selectivity of the immunosensor is good.