| Molecular imprinting?MIT?refers to the preparation of a polymer that has specific selectivity for a particular target molecule?template molecule/imprint molecule?,the molecularly imprinted polymer?MIP?.It has a wide range of applications in a number of applications because of its specific characterization and specific recognition and practicability for target molecules due to molecularly imprinted polymers.In addition,carbon nanotubes have a good volume effect,surface effect and quantum effect,so that in the field of materials,catalysis,sensing has been widely used.Metal nanoparticles have quantum size effect,surface effect and quantum tunneling effect,so they can be used as an ideal material for constructing functional nanostructures.The combination of carbon nanotubes,gold nanoparticles,and molecular imprinting techniques is used in sensor preparation to produce rapid,sensitive,and highly selective detection of many substances in the environment.The research work of this paper is as follows:1.The copper ion imprint electrochemical sensor was successfully constructed by surface self assembly and electropolymerization method.The electrochemical performance and selectivity of the imprinted sensor were studied by cyclic voltammetry and differential pulse method.The experimental results show that the electrode surface is modified by the functional layer of the nanometer material,which greatly increases the sensitivity of the sensor.At the same time,there are many bonding sites on the imprinted polymeric film,which makes the Cu2+have good selectivity.The logarithm of peak current and Cu2+concentration showed a good linear relationship in the concentration range of 5×10-101×10-6 mol L-1.The linear regression equation was Ip=-10.24LgC-199.9?Ip:?A,C:mol L-1?with a correlation coefficient of 0.9923 and a detection limit of 1.67×10-10 mol L-1?S/N=3?.At the same time,the prepared ion imprinting sensor can be used for the detection of copper ions in tap water samples.2.We use tetramethylthiophenol?p-ATP?as functional monomer,methyl parathion?MP?as template molecule prepared the methyl parathion molecularly imprinted electrochemical sensors by electrochemical polymerization method.The imprinting effect was characterized by cyclic voltammetry and electrochemical impedance spectroscopy and differential pulse method.The experimental results show that it is feasible to prepared molecularly imprinted electrochemical sensors to detect methyl parathion?MP?by electro-polymerization of tetraaminothiophenol?p-ATP?.At the same time,the logarithm of methyl parathion concentration had a good linear relationship with the peak current in the range of 1×10-81×10-5 mol L-1.The linear regression equation is Ip??A?=47.82+4.178LgC(mol L-1),the correlation coefficient is 0.9941,the detection limit is 3.3×10-9mol L-1?S/N=3?.Finally,the prepared samples were used to measure the methyl parathion in the actual sample,and the effect was good.Compared with other methods,this method did not need to be pretreated in advance,good selectivity,high sensitivity and good reproducibility,Which provides a very effective method for the analysis of methyl parathion?MP?.3.A novel two-functional monomer 2,4-dichlorophenoxyacetic acid?2,4-D?molecular imprinting based on carbon nanotubes modified by 2,4-D as a template molecule was developed using o-phenylenediamine and resorcinol as bifunctional monomer.Due to the advantages of multi-walled carbon nanotubes and bifunctional molecularly imprinted polymers,the detection of 2,4-D molecules by the sensor showed high sensitivity and good selectivity.Under optimal conditions,The concentration of 2,4-D had a good linear relationship with its peak current in the range of 7.3×10-9 to 2.96×10-7 mol L-1.The linear regression equation was Ip??A?=21.15+0.0191C(mol L-1),the correlation coefficient was 0.9867,and the detection limit was 2.43×10-9 mol L-1?S/N=3?.Finally,the prepared samples were used to measure the 2,4-D in the actual sample,and the effect was good. |
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