Carbon Nanotubes Modified Electrodes Used In Biochemical Detection

With the improvement of people’s living standard, the problem of food health and safety and living environment quality testing are getting more and more Social concerns. How to test food and environment accurately and conveniently is becoming an important issue in the field of application of technology. As nano materials getting a wide range of research and application, people start to concern the application of nanoscience in biochemical detection. The paper chooses two kinds of biochemicals in the area of food safety and health – Ractopamine and Riboflavin and points test method using carbon nanotubes modified electrodes.The current main biochemical detection methods are Chemiluminescence, Capillary Electrophoresis, High Performance Liquid Chromatography, Enzyme-linked immunosorbent assay and electrochemical method. The electrochemical method has many advantages compared with other biochemical detection method, such as Shorter test cycle, easier to operate, better repeatability and higher sensitivity and can be used to get the nature of biochemical organic according to electrochemical analysis of maps and plots.The carbon nanotubes are getting more and more application with its good electrochemical catalysis ability. Modifying carbon nanotubes in the surface of electrode can increase the specific surface area of the base electrode and increasing the number of electrode surface catalytic sites by means of organic functional groups through carbon nanotubes. The electrochemical reaction of electrodes are strengthened which can achieve a more efficient and precise measurement.Aiming at the shortcomings of traditional carbon nanotubes modified electrode, such as carbon nanotubes distributed random, carbon nanotubes poor adhesion on the electrode surface and selectivity of base electrode, the curable organic matter carbon nanotube modified electrode are prepared. And through the analysis of the carbon-nanotubes(CNTs)/Ni composite modified electrode, a new type of metal-based polymer matrix composite carbon nanotube modified electrode are prepared. This new electrode can improve the electrode surface carbon tube uniform implanter, enhance the sensitivity of the device and achieve a reliable mechanical and electrical connection of the carbon nanotubes and the metal structure.The effect of process optimization can be characterized by electron microscopy and the electrochemical reaction. Field emission electron microscope can get the feature of morphology, density and of nanotubes on the surface of the electrode. The results show that the nanotubes with larger diameter have better interface situation and electrocatalytic performance. At the same time, reasonable controlling of the etching time has a positive effect for the Electrode catalytic ability increasing. The oxidation- reduction peak of volatile organic compounds carbon nanotubes modified electrode rises 100% than the bare electrode. The oxidation- reduction peak of the curable organic matter carbon nanotube modified electrode rises 100% than the bare electrode. After 400 cycles, these two modified electrodes both decrease 30%. But after 300 cycles, the curable organic matter carbon nanotube modified electrode decreased more slowly than volatile organic compounds carbon nanotubes modified electrode. The aging problem of these electrodes are also discussed. The electrolyte can react with carbon nanotubes and weak the carbon tube catalysis of redox reactions.The paper focuses on the test of ractopamine and riboflavin using carbon nanotubes modified electrodes.For the inspection of ractopamine, the effects of different type of carbon nanotubes are discussed. The electrochemical properties of volatile organic compounds carbon nanotube modified electrode and curable organic matter carbon nanotube modified electrode are compared. The conclusion is curable organic matter carbon nanotube modified electrode has better electrochemical properties, interface situation and electrode reuse.For the inspection of riboflavin, the electrochemical properties of the metal base explants cloth electrode and volatile organic compounds carbon nanotube modified electrode are compared. The metal base explants cloth electrode has a less △Ep which means a stronger catalysis ability. At the same time, the peak currents are all enhanced, the oxidation peak current value increased 6.59 times and the reduction peak current value increased 4.59 times, which also means the metal base explants cloth electrode has a stronger catalysis ability. The detection limit of the metal base explants cloth electrode is 3.5×10-7M which is lower than the 5×10-6M mentioned in previous paper. After 100 cycles, the oxidation peak voltage deviation is only 0.1% and the electrode surface does not appear any morphological changing which means the electrode has a good stability.