Studies On Electrochemical Immunosensors Based On Nanomaterials For Human Chorionic Gonadotrophin

A biosensor is the use of molecular biological active substances (such as enzymes, proteins, DNA, antibodies, antigens, membrane, cell, etc.) to identify the function of the biochemical reactions into usable output signal, which the living matter and chemical matter detection devices. Electrochemically based immunosensors are valuable analytical tools for monitoring of the antibody or antigen as the advantages of short response time, high sensitivity, high specificity and easy manipulation, which combined the merits of electrochemical technology and immunoassay. Nanomaterials are often used as the satisfactory matrix for the immunosensor because of their large specific surface area, favorable biocompatibility and high surface reaction activity, which could increase the amount of immobilized biomolecules and keep their activity well. Therefore, nano-materials (such as nanoparticles, nanotubes, nanowires, etc.) are widely applied to biological sensors. Based on the above considerations, this article is based on the above considerations, exploration and research is based on a series of nano-materials, bio-molecules as the carrier of fixed methods.The main research work are as follows:: 1. Investigated the immunosensors based on the magnetic nanophase materialsDesigned a simple and rapid preparation of sensors with high sensitivity and good selectivity, reproducibility and long-term stability, etc., can be used in the detection of other immune molecules. A novel disposable immunsensor applied to the determination of a-1-fetoprotein (AFP) has been developed for the immobilization anti-a-1-fetoprotein (anti-AFP) to the Fe3O4-cross-linked polyaniline nanocomposite (Fe3O4-PANI) modified on indium tin oxide (ITO) conductive glass developed measured a-1-fetoprotein (anti-AFP) levels of immune sensors. The electrochemical behaviors and modified procedure of the immunosensor were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimized conditions, the immunosensor displayed high sensitive to AFP with a linear range from 1 and 120 ng·mL-1, with a correlation coefficient of 0.9983, and the low detection limit of 0.6 ng·mL-1 (S/N=3).2. Electrochemically deposited nanocomposite of carbon nanotubes and chitosan for detection of human chorionic gonadotrophinConstruction of the signal amplification of CEA immunosensor. Compared with traditional methods, this method has three obvious advantages:First, the use of polycarbonate (PC) film as a barrier material and grooming space deposition of three-dimensional gold clusters and nanowires of gold adsorption of sulfur to enhance its three-dimensional structure in the above provides a large surface area and clear the efficiency of electron transfer increases. Secondly, the preparation of Au-CS-PB-Fe3O4 as a marker of the physical properties of magnetic nanoparticles and nanoparticles on the surface advantages. Finally, both GOD and HRP enzymes to magnetic nanoparticles labeled. In the two enzymes under the effect of multiple catalytic amplification can enhance the electrochemical response signal again to improve the sensitivity of immunosensor. Preparation of surplus which is sensitive, low-cost, low detection limits, wide linear range of current immunosensor. Under optimized conditions. This approach provided a detection limit of 0.019 ng·mL-1 and the linear range covered from 0.05 to 200 ng·mL-1.