Study On The Application Of Electrochemical Sensor In Clinical Diagnosis Based On Noble Metals Nano Materials

With the characters of good selectivity, high sensitivity, fast analysis speed, easy operation and the feasible in-vivo online analysis, electrochemical immunosensors play an increasingly important role in the study of analytical chemistry, which have been widely used in clinical diagnosis, food inspection, environmental monitoring and drug analysis, etc. In recent years, nanotechnology has been gradually applied to the field of biosensors, and gotten a breakthrough. Therein, noble metals nanomaterials with good biocompatibility, high electric catalytic activity and fast electron transferring rate have gained more and more attentions in fabricating biosensor. The research is mainly divided into four parts as follows:1. This section presents an overview of the definition, working principle and classification of the electrochemical biosensor, immunoassay, immunosensor and electrochemical immunosensor; introduces the characteristics of nano materials and using nano materials in the application of biological sensors; introduces the applications of nano-materials in the immunosensor as well as the applications of immunosensors in the detection of tumor.2. In this chapter, we mainly synthesized a new kind of palladium-mesoporous TiO2nanoparticles(f-Pd-TiO2), and used it as a label apply to create electrochemical immunosensor in the detection of carcinoembryonic antigen (CEA). We use nitrogen doped graphene tag Ab1of CEA, f-Pd-TiO2tag Ab2of CEA, build a sandwich-type immunosensors for detection of CEA. The proposed immunosensor shows wid linear range (5～1000pg·mL-1), low detection limit (2.21pg·mL-1), satisfactory reproducibility, selectivity and stability. The precision, reproducibility and stability of the immunosensor were acceptable. The proposed strategy could be easily extended to fabricate immunosensors for other tumor markers.3. Carboxyl functionalized graphene was synthesized in this chapter and used for fixing antibody(Ab1); under the characteristics just like good stability and film forming of ionic liquid (IL), we used IL fix carboxyl functionalized grapheme-Ab1onto the electrode surface. We synthesized amination of mesoporous TiO2nanometer ball, used for adsorption of cadmium ion and fixed Ab2. This experiment we build a sandwich-type immunosensors for detection of breast cancer tumor markers carbohydrate antigen15-3(CA15-3), and then we studied immunosensor’s performance by cyclic voltammograms and square wave voltammetry. The proposed immunosensor shows wid linear range (0.02～60U·mL-1), low detection limit (0.008U·mL-1), satisfactory reproducibility, selectivity and stability. The precision, reproducibility and stability of the immunosensor were acceptable. The proposed strategy could be easily extended to fabricate immunosensors for other tumor markers.4. This chapter we synthetized IL/pd nanorods/graphene,which has good electrical response for glucose detection, and then we used it to build a glucose electrochemical sensor. The sensor shows wid linear range (0.5～16mmol·L-1), low detection limit (0.2mmol·L-1), good selectivity and reproducibility. The result is satisfactory. The advantages of the glucose sensor with simple building process and the ultra-sensitivity may provide a potential application for clinical diagnosis.