| Electrochemical immunosensors are valuable analytical tools for monitoring of the antibody or antigen having the advantages of short response time, high sensitivity specificity and easy manipulation, which combined the merits of electrochemical technology and immunoassay. They have been widely used for clinical diagnosis; environmental inspection; food analysis; military monitoring; industrial production and so on. The enhancement of immunoassay signal is always important in immunoassay study, which is vital to improve the assay sensitivity. Therefore, this research focuses on the preparation of nanomaterials, the construction of the immunoreaction interface and the development of sensitivity enhancement electrochemical immunosensors.The detailed contents are shown as follows:1. Combination of enzyme-catalyzed silver deposition and the nanoparticles enlarged further, a novel ultrasensitive, successive signal amplification electrochemical immunosensor based on an indirect competitive assay was developed for the determination of ochratoxin A（OTA）. Under the optimized conditions, this immunosensor showed a good linearity dependency upon the concentration of OTA in the range from 1.0×10-3 ng/mL to 100 ng/mL with a detection limit of 7.8×10-4 ng/mL.2. A highly sensitive electrochemical immunosensor for haptene based on prussian blue and Chitosan-Au NPs composite was developed. H2O2 could be directly reduced by prussian blue nanoparticles, thereby increasing the sensitivity of immunosensor. The Chitosan-Au NPs were modified to offer large specific interface and desirable biocompatibility to absord biomacromolecule. Under the optimized condition, the response current of the proposed immunosensor decreased linearly in concentrations ranges of ochratoxin A from 5.0×10-3 ng/mL to 100 ng/mL with a detection limit of 3.0×10-3 ng/mL. |
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