Preparation Of Functional Composite Electrochemical Biosensor By Electrodeposition Method And Its Application

Since the 1990s,with the rapid development of chemically modified electrodes,various modification methods and materials have been continuously explored and developed,and then applied to various fields such as environment,food,energy,and medicine.Among them,electrodeposition technology is favored by researchers because of its simple operation and green safety.Electrochemical biosensors prepared by electrodeposition techniques can effectively improve their electrochemical performance.In this context,series electrochemical biosensor modified with the functional composite material is prepared by electrodeposition on the surface of glassy carbon electrode,which is applied to the quantitative detection of environmental pollutants and small molecules.It mainly includes the following contents:(1)An electrochemical sensor was successfully prepared by ammoniation synergistic phosphate activated glassy carbon electrode(CA-GCE),and then studied and characterized by electrochemical impedance spectroscopy and cyclic voltammetry.The experimental results show that CA-GCE exhibits superior electrocatalytic performance for hydroquinone,catechol and resorcinol.In addition,the reaction principle of hydroquinone,catechol and resorcinol on the surface of CA-GCE was also studied.The experimental results show that their kinetic reaction controlled by the adsorption.Under the optimal conditions,the detection ranges of hydroquinone,catechol and resorcinol were 1-300,10-300 and 5-200 ?M,respectively,and the detection limits were 0.47,0.23 and 0.46 ?M,respectively.The sensor also has good anti-interference ability and stability,and is expected to be applied to the detection of actual contaminated samples.(2)NiS nanoparticle modified electrochemical biosensor was prepared by the electrodeposition technology which a metal ion complex used as a precursor,thioacetamide used as a reducing agent and a coating agent.The modified electrode was then characterized by X-ray energy spectroscopy,field emission scanning electron microscopy,cyclic voltammetry and electrochemical impedance spectroscopy.The sensor exhibits excellent electrocatalytic oxidation performance for hydrogen peroxide and glucose due to its small size of NiS nanoparticles.The catalytic mechanism of the sensor was then studied.Under the optimal conditions,the detection range of ydrogen peroxide and glucose is 1-5000 and 1-1000 ?M,respectively,and the detection limits are 0.257 and 0.3 ?M,respectively.The experiment result also verified that the sensor's anti-interference performance is good.Finally,the fabricated sensor was also applied to the detection of hydrogen peroxide and glucose in actual serum samples with satisfactory results.(3)An electrochemical was first electrodeposited amino-based reactive groups by the potentiostatic method in a glassy carbon electrode,and then the nano-gold-platinum alloy was modified to the surface of the aminated glassy carbon electrode by cyclic voltammetry.The sensor was characterized by cyclic voltammetry and AC impedance method and then the conditions were optimized.The sensor has excellent electrocatalytic oxidation of glutathione.Based on this,a novel electrochemical biosensor for rapid and sensitive detection of glutathione was constructed.The detection range and detection limit of the sensor for glutathione were 0.1-11 ?M and 0.051 pM,respectively.The sensor also has good selectivity and reproducibility,and is expected to be applied to the actual sample detection.