Preparation Of Transition Metal Nitride And Its Application In The Detection Of Environmental Micro-pollutants By Molecularly Imprinted Sensors

In recent years,with the rapid development of economy,environmental pollution has become a global problem that can not be ignored.In animal husbandry,aquaculture and other industries,such as antibiotics,pesticides,phenols and other environmental micro pollutants are discharged into the ecological environment on which human beings depend for survival,which poses a serious threat to the ecological balance.At present,in the face of increasingly serious environmental problems,it is urgent to develop a highly selective and sensitive detection method for environmental micro pollutants.After a long time of research,the electrochemical sensor has been widely concerned by researchers due to its advantages of simple operation,high speed and high sensitivity.With the development of nanotechnology,transition metal nitride nano array materials have been proved to improve the electrochemical response and stability of electrochemical analysis.Therefore,in this paper,a variety of molecularly imprinted electrochemical sensors for the detection of environmental micro pollutants have been constructed by the combination of molecularly imprinted technology and electrochemical sensor with the transition metal nitride nano array material as the base electrode.These studies enrich the electrochemical methods for the detection of environmental micro pollutants,and expand the application of transition metal nitride nano array materials.In this paper,the following research has been done:1.Cobalt nitride precursor was grown in situ on the surface of carbon cloth(CC)by hydrothermal method,and the precursor was nitrided by ammonia gas through nitriding reaction to synthesize nitride with good conductivity and large specific surface area Cobalt nanowire array(Co N/CC).Molecularly imprinted polymer(MIP)was prepared by a modified bulk polymerization method using Tylosin(TS)as a template molecule and ?-methacrylic acid as a functional monomer under the action of a crosslinking agent and an initiator.Here,based on the clever combination of MIP and self-supporting Co N nanowire arrays(Co N/CC),a stable molecularly imprinted electrochemical(MIP-EC)sensor was developed.Under the optimal conditions,the MIP-EC sensor achieves TS detection in a concentration range of 8.6×10-11-6.7×10-5 mol L-1,and the detection limit(LOD)is 5.5×10-12 mol L-1.The MIP-EC sensor has a wide linear range,low detection limit,high selectivity,reproducibility and stability.The usefulness of the MIP-EC sensor was tested in surface water and soil samples.The proposed MIP-EC sensor has a simple manufacturing process,can provide a universal and reliable method,and has great potential application value for the detection of small molecular pollutants.2.A self-supporting Fe3N-Co2N/CC nanoarray with good conductivity and large specific surface area was prepared by hydrothermal synthesis and ammonia nitriding reaction.Ampicillin(AMP)was used as a template molecule through a modified bulk polymerization method.MIP was prepared by using N-dimethylacrylamide as a functional monomer under the action of a crosslinking agent and an initiator.Fe3N-Co2N/CC nanoarrays provide an ideal substrate for in-situ polymerization to form MIP adsorption.Therefore,a sensitive and stable MIP-EC sensor was constructed for the detection of AMP.Under the optimal conditions,the developed MIP-EC sensor can detect AMP in a concentration range of 5.56×10-9×10-3 mol L-1.The detection limit is 3.65×10-10 mol L-1,which shows high selectivity,reproducibility and stability.Therefore,the use of MIP-EC sensors is very promising for sensitive and selective electrochemical measurements and food safety testing.3.In the field of biosensors or sensors for electrical analysis,people pay more attention to the non washing detection of small molecular pollutants in real samples.The in-situ grown Co N nanoarray on CC was used as the working electrode to prepare the electroactive material toluidine blue(TB)solution,and MIP was prepared by the improved bulk polymerization method.Based on the direct electrochemical irreversible oxidation of Fluorene-9-bisphenol(BHPF)on the Co N nanoarray electrode,we developed a ratiometric MIP-EC sensor to detect BHPF in serum and tap water.With the increase of BHPF concentration,more BHPF and less TB are exposed on the electrode surface.Therefore,the value of ?IBHPF increases gradually,while the value of ?ITB decreases gradually,and the value of ?ITB/?IBHPF as instruction response decreases gradually.The ratiometric method is established to realize BHPF detection with high sensitivity and reliability.BHPF can be detected in the concentration range of 1.90×10-7-9.4×10-4 mol L-1,and LOD is 6.33×10-8 mol L-1.The ratiometric MIP-EC sensor has been proved to have strong anti-interference ability,good detection reproducibility and stability of bhpf.This work can provide theoretical and practical guidance for the detection of other small molecules.