Preparation Of Acetylcholinesterase Sensor Based On Mesoporous Carbon Materials And Application Of Organic Phosphorus Detection

The use of organic phosphorus pesticides is very extensive,which probably inhibit the activity of acetylcholinesterase in humans and animals,causing harm to the human body.At present,common methods for the detection of pesticide residues are chromatography and mass spectrometry,which have some disadvantages such as long time,cumbersome operation,and high price.In recent years,electrochemical enzyme sensor,with excellent properties such as high sensitivity,fast response,and low cost,has emerged quietly.They have become a class of tools for rapid detection and analysis,and they have been successfully applied to medicine,food,environment and military applications and other fields.Electrochemical enzyme sensor detection method has the characteristics of high efficiency and rapid detection,suitable for on-site detection and a large number of sample screenings.Therefore,the electrochemical sensor of acetylcholinesterase(ACh E)is gradually being widely used for the detection of organophosphorus pesticides.Mesoporous carbon materials have attracted wide attention due to high specific surface area and excellent electro catalytic properties.In view of this,two kinds of carbon materials-mesoporous hollow carbon spheres and magnetic mesoporous hollow carbon spheres are synthesized.The acetylcholinesterase sensors based on two kinds of mesoporous carbon materials were prepared by physical adsorption method and glutaraldehyde cross-linking method.The properties of the carbon materials were characterized by Scanning electron microscopy,Transmission electron microscopy,X-ray diffraction spectroscopy,and Fourier infrared spectroscopy.The selection of enzyme electrode conditions such as glutaraldehyde concentration and enzyme content were discussed.Then,the influence of theconcentration of the enzyme substrate acetylcholine chloride and p H value on the performance of the sensor was also examined.The working conditions of the enzyme sensor are optimized,and finally the detection of malathion is performed using the optimized acetylcholinesterase sensor.The inhibition rate of ACh E-MHCS-GCE electrochemical sensor and ACh E-Fe3O4@MHCS-GCE electrochemical sensor showed a linear relationship with the pesticide concentration ranged from 0.01 to 30 ppb and 30 to 100 ppb.The detection limit of Malathion pesticide of ACh E-MHCS-GCE electrochemical sensor and ACh E-Fe3O4@MHCS-GCE electrochemical sensor is 0.0148 ppb(S/N=3)and 0.0182 ppb(S/N=3),respectively.