Fabrication Of Graphene Like-based Electrochemical Sensing Platform And Their Application

Antibiotics have been widely used in animal husbandry as veterinary drugs and feed additives.However,excessive or misuse of antibiotics can lead to antibiotic residues and drug-resistant bacteria.It is not only a serious threat to human health,but also will destroy the ecological balance.So it is of great significance to build sensitive methods for antibiotics detection.Due to its simple equipment,easy operation and the advantages of fast analysis speed,electrochemical sensor has aroused the concern of medical testing.Given this,in this thesis,antibiotic electrochemical platforms were constructed based on graphene like functional nanocomposite,new electrochemical sensor analysis methods were built based on this principle,the main research works were as follows:1.3D nitrogen impurity graphene hydrogel/molybdenum disulfide?3D NGH/MoS₂?was prepared by one-step hydrothermal method,the material has the outstanding performance of high surface area,good electrical conductivity and high efficient electron transfer,a mass of biological recognition molecules could be loaded.Photoelectrochemical?PEC?sensing interface was built to recognize chloramphenicol?CAP?took the advantage of the ?-? effect between CAP and 3D NGH/MoS₂.The aptamers were absorbed on the surface of 3D NGH/MoS₂,hindering the mass transfer,reducing the photocurrent intensity significantly,after specific binding with CAP,the aptamers would break away from the surface of NGH/MoS₂ and the photocurrent intensity restored.A PEC aptasensor of CAP was developed based on this principle.Under the optimal conditions,there was a good linear relationship between the restored photocurrent intensity and the concentration of CAP,the linear range is 0.1 ³00 nmol L-1?R2 = 0.998?with the low detection limit of 0.03 nmol L-1,the sensor showed good selectivity and reproducibility,which could be used to the rapid detection of CAP.2.Graphite carbon nitride/graphene hydrogel?g-C₃N₄/GH?nanocomposite was prepared by one-step hydrothermal method.Comparative experiment found that g-C₃N₄/GH can produce much stronger electrochemical luminescence?ECL?signal interact with K2S₂O8,indicating that the addition of GH can promote the electrochemical luminescence signal of K2S₂O8 system.The sensing interface was built to recognize tetracycline?TET?take the advantage of the ?-? effect between TET and g-C₃N₄/GH.The adsorption of aptamer hindered the material transfer andreduced the ECL intensity,the aptamer would break away from the surface of g-C₃N₄/GH when combined with TET,then the ECL intensity was restored.A ECL aptasensor of TET was developed based on this principle.Under the optimal conditions,there is a good linear relationship between the sensor and the concentration of TET,the linear range is 0.5 nmol L-1 1 ?mol L-1 with the low detection limit of 0.17 nmol L-1.The sensor showed good selectivity and reproducibility,which provided a new idea for antibiotics detection.3.Ultra-thin carbon nitride/tungsten oxide?utg-C₃N₄/WO₃?nanocomposite was synthesized by the method of calcination.Confrontation test found that the introduction of utg-C₃N₄ can improve the electric conductivity and charge transfer efficiency of WO₃,prolong the life of photon-generated carriers,and inhibit the separation of photoinduced electronic-holes.A sensitive PEC sensor was constructed based on the principle of the oxidizing reaction of glucose by the holes,and thus enhanced the photocurrent.Under the optimal conditions,the sensing platform showed a wide linear range?0.01 7.12 mmol L-1?,a low detection limit?3.33 ?mol L-1?,good selectivity and reproducibility,a new method was provided for the construction of sensitive glucose determination platform.