Construction And Performance Study Of Nanocomposite-based Electrochemical Biosensor

Biochemical warfare agents pose a serious threat to national security,so research on biochemical warfare agent detection and defense has an urgent need.Based on strong specific biometric components and high sensitivity electrochemical analysis techniques,electrochemical acetylcholinesterase sensors and electrochemical aptamer sensors were constructed,and their sensing properties and sensing mechanisms were studied.RGO-PDA and Au NPs and Ag NPs nanomaterials were prepared first and then characterized by UV-Vis,SEM and TEM.The nanomaterials and ACh E were composited and fixed on the GCE surface to construct the sensor GCE/RGO-PDA-Au NPs-Ag NPs-ACh E-CS in the presence of CS to optimize the structure and test conditions of the sensor.The results show that the sensor can achieve a detection limit of 9.1 p M for methyl parathion and a wide linear detection range of 76 p M～3.04 μM,indicating that the sensor has practical value.Then,the hairpin probe modified with methylene blue was self-assembled on the Au E surface,and the electrochemical nucleic acid aptamer sensor Au E/MB/MCH was coverd by MCH.The test for isocarbophos was carried out using a competition method.The possible formation of aptamer substrates was analyzed.Combine experiments to select for suitable aptamer substrates.The linear detection range of the electrochemical aptamer sensor for isocarbophos is 3.46 n M～3.46 m M,and the detection limit is 43.83 p M.The results show that the electrochemical acetylcholinesterase sensor and electrochemical aptamer sensor have excellent stability,good anti-interference ability and excellent preservation performance.