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Background biosensor has good selectivity, high sensitivity, speed of analysis, ease of operation, low price, even real-time online detection and in vivo analysis has therefore become one of the current research focus. The current, third-generation electrochemical biosensors based on direct electron transfer on the electrode is the research focus of the current biosensors, nanomaterials have unique physical and chemical properties of the third-generation electrochemical biosensors build a new way. The use of nano-material is larger than the surface area characteristics and excellent biological compatibility, increasing the amount of antibody immobilized on the electrode, and antibodies to maintain the biological activity, thereby improving the sensitivity of the sensor. How the variety of nano-complexes and particles effectively fixed at the electrode surface, and maintain the synergistic increase the capacity of the electron transport is the most important part of the biosensor research and development. Objective To establish the sensitivity and specificity of PSA current immunosensor based nanocomposites particles modified to optimize the experimental conditions that affect the rate of electron transfer and electrochemical properties characterization study. Comparison with the existing test for prostate-specific antigen chemiluminescence, the feasibility analysis for the clinical detection of prostate-specific antigen (PSA) and the main advantages and disadvantages. Materials and Methods 1, washed with acetone, ethanol, distilled water, ultrasonic cleaning oxide, indium tin (ITO). 2, the multi-walled nanotube (MWNT) placed Ultrasound 4 h in 30% nitric acid to introduce a carboxyl group, and then washed with double distilled water to neutral, and dried. Preparation of Prussian blue - chitosan (CS-PB) nanocomposite gold nanoparticles (Aunano), Prussian blue - gold nanoparticles (Aunano-PB) nano-complex, amino-silanized - glucan - iron oxide (AEAPS-Dextran-Fe3O4) magnetic nanocomposites. 4, by UV spectrophotometer observed CS-PB the Aunano-PB, AEAPS-dextran-of Fe3O4 characterized absorption peak and TEM observation of the morphology and diameter of the CS-PB, AEAPS-Dextran-Fe3O4, and with an atomic absorption spectrophotometer iron content AEAPS-Dextran-Fe3O4, anthrone - sulfuric acid method glucan content. The 5 the the immunosensor preparation of current BSA / anti-PSA / Aunano / CS-PB / MWNT / DpAu / ITO and BSA/anti- PSA / Aunano / AEAPS-Dextran-Fe3O4 / Aunano-PB/ITO. 6, the optimal experimental conditions, in 0.1 mol / L PBS (pH = 7.0) buffer, using cyclic voltammetry electrochemical characterization of the prepared sensor, and observe the detection sensitivity of the sensor, the linear response range. 7, do methodological experiment (interference experiment, stability, repeatability, recovery experiments and comparative experiments) to evaluate the performance of the sensor. 1 by ultrasonic cleaning, to give clean ITO electrodes alternate. 2 by ultrasonic reaction in 30% nitric acid, so that the MWNT the successful introduction of the carboxyl group. Successfully prepared CS-PB nanocomposites Aunano Aunano-PB nanocomposite material, AEAPS-Dextran-Fe3O4 magnetic nano-composites, and characterization by ultraviolet spectroscopy and transmission electron microscopy. 4, through the optimization of the experimental conditions, the initial preparation can detect the PSA the current type immune sensor and detection methods. Under optimum conditions, the sensor can be completed in 10min detection, compared with traditional immune sensor, the sensor detects a higher sensitivity, wider linear range, good stability, reproducibility, and recovery. 5, the electrochemical immunosensor constructed novel nano composite modified with traditional immunoassay method do comparative experiments, similar detection results of the clinical specimens, prepared as the sensor can be used for clinical specimens. CS-PB nanocomposites Conclusion Aunano-PB, AEAPS-Dextran-Fe3O4 and nano particles Aunano, MWNT through self-assembly, electro-polymerization technology, successfully prepared two tag-free PSA current immunosensor. Preliminary evidence of the method is simple, fast response, and specificity, the increase in the fixed amount of antibody, thus greatly improving the immune detection linear range and sensitivity of the sensor.
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