Research Of Penicillinase Biosensor Modified By Electric Aggregation Dye

At the same time of the continuous development,progress of modern society and, people’s living standard continues to improve,people’s awareness of green food is more and more intense, more and more pressing. Which makes people’s food structure has undergone great changes, it increased the consumption of meat, milk, eggs and other animal products, animal husbandry has been a rapid development and completion large quantities of the modern large-scale livestock farms. Penicillin is one of the most commonly used antibiotics in the veterinary medicine, it is very very significant to detect the residual significance.The method for the detection of penicillin contains microbiological method, physical and chemical detection method (high performance liquid chromatography, gas chromatography) and immunoassay. Microbiological method with the advantage of easy operation, small amount of sample, easy processing, etc.; but it susceptible to the interference of other antibiotics in the test samples through the testing process, relatively low specificity and sensitivity, and detection of a very long time, the detection limit can not meet the requirements. Physical and chemical analysis, accuracy, sensitivity and accuracy are high, with the advantages of low detection limit, the experimental results are accurate and reliable, but the equipments used by physical and chemical analysis method are very expensive and complicated operating procedures, the professional and technical requirements is very high,and the speed of detection is also limited, this method is not suitable for popularization and promotion, not to meet the needs of today’s society on the detection of fast and in a timely manner and even online testing. Immunosorbent assay with high sensitivity and specificity, but the development process of this method requires a lot of money and time, and the sample preparation process is cumbersome and complex, difficult to quantify, in addition this method is difficult to achieve on-site testing, can not meet the rapid,no damage and and other requirements. In view of these shortcomings of these current method, we urgently need to establish a convenient, high accuracy and sensitivity, inexpensive and can be used for the detection method of the on-site analysis. The sensor is an inexpensive, easy to use, accuracy and reliable analysis tools, dye-modified sensor makes the better performance of the sensor, the electrochemical activity becomes higher. In this work, thionine and bromophenol blue dye, as a modifier, modified on glassy carbon electrode surface by electrochemical polymerization. And combinated the different membrane order with penicillinase Poly-bromophenol blue penicillinase sensors and penicillinase sensor modified by electroless polymerization of thionine which can be directly used for the detection of penicillin G analysis were prepared, respectively. The basic content of the paper is as follows:1. Using cyclic voltammetry method to research the feasibility of electric aggregation of thionine and bromophenol blue dye, the electrodes modified with electric polymer by two dyes were successfully prepared. Its electrochemical activity demonstrated that the electrochemical activity of the modified glassy carbon electrode was much higher than the bare glassy carbon electrode.2.Using Bromophenol blue electric polymerization polymer film immobilized the penicillinase on a glassy carbon electrode, poly-bromophenol blue penicillin enzyme electrode for the detection of penicillin residues was successfully prepared. The experiments show that the best condition was sensor bromophenol blue electric aggregate number of turns:-19laps, the optimum pH value:6.1, and temperature:24.6℃. Under this condition, the sensor showed a good detection performance, strong anti-interference,and good reproducibility and stability. The sensor showed a good linear to detect penicillin G sodium concentration in the solution from0.1to2.6μg/mL and the detection limit was0.2μg/L, the regression equation was y=3.1959x+16.22(x:penicillin G sodium concentration, μg/mL) with the regression coefficient of0.9985, the recovery rate is between 94.4%-103%..3. Thionine polymer film was formed on glassy carbon electrode surface by using electrochemical polymerization then through the cross-linking method, penicillinase was fixed on the polymer film surface, and picillinase sensor was successfully prepared which modified by electroless polymerization of thionine. The experimental results showed that the optimal conditions of enzyme immobilization on the sensor were: concentration of glutaraldehyde was2.5%, concentration of bovine serum albumin was6.6%, time of immobilization was2.4h; And the best performance conditions were as follows:pH6.7, temperature26.8℃, the amount of enzyme50.5μL. The sensor was determined by cyclic voltammetry in PBS of penicillin G sodium whose concentration was from0to10μg/mL. And it showed a good linear relationship between concentration and peak current during the concentration from0.08to1.0μ.g/mL, the detection limit was0.05μg/L The regression equation was y=18.218x+23.067(x:penicillin G sodium concentration, μg/mL), the regression coefficient was0.9973.