Research On Biochemical Sensor And The Detecting Device For Detecting Explosives

Explosion is a means most commonly used by terrorists, which also causes great threat to social stability and national security. Therefore, it is necessary to take effective methods to detect the hidden explosives, and there has far-reaching and realistic significance on human security issues for taking a research on the explosive detective technology. Owing to the sensitive response of piezoelectric quartz crystal and the specific recognition function of molecular imprinted polymer, a kind of explosive detection method based on Molecular Imprinting Technology (MIT) and biochemical sensor is studied in this paper.Molecularly Imprinted Polymers (MIPs) were used as the recognition element based on the principle and composition of biochemical sensor by serious selection. In this paper, MIPs of explosive molecules of TNT, HMX, RDX and ammonium nitrate are prepared respectively by the surface molecular imprinting method with the meth acrylic acid MAA as functional monomer, chloroform as solvent, and ammonium persulfate as the initiator, respectively. According to the static balance test method, the adsorption properties of these MIPs were studied and also their selective properties were verified through the selective experiment. Piezoelectric crystal was chosen to be the conversion element. The molecularly imprinted piezoelectric sensor was made by using appropriate method to fix the identify component on the conversion element. Secondly, the overall structure principle of the detecting device was analysis detailed, each module circuits which include the oscillation circuit, mixer circuit, filter circuit, etc. are designed. The difference frequency between the detection crystal and the reference crystal is measured by combining the above circuits together, based on which the presence of explosives are determined and the purpose of detecting explosives is achieved.The MIPs adsorption experiment results show that the prepared MIPs have a better combination with their corresponding explosive template molecules. And also the biochemical sensor has good sensitivity with the detection limit is reach to 10-6g at least. Eventually, the sensor was applied to explosive detection experiments, and the regeneration of the sensor was studied through some experiments, which suggest that the sensor has good regeneration performance and can be reused for dozens of times. The sensor is small, portable and low cost, which is expected to be used in airports, train stations and other security departments.