Investigation Of Novel Electrochemical Sensors Based On Metal-based Nanomaterials

In the past few decades,nanomaterials have been widely used in many fields.Among them,natural and man-made nanomaterials have become one of the first-choice materials for constructing electrochemical sensing interfaces due to their unique morphology,structure and excellent performance.In this dissertation,three non-enzymatic noble metal based electrochemical sensors are built to detect different analytes,such as glucose,catechol,hydroquinone and hydrogen peroxide,with high sensitivity,excellent selectivity,and wide linear range.These electrochemical sensors could also be applied to detect different analytes in actual samples.The research results of this work provide new way for the preparation of noble metal-based electrochemical sensors for different analytes detection.The dissertation is divided into four chapters.The main work can be divided into the following two categories:1.Electrochemical sensing of glucose based on Au-ZnONRsZnONRs vertically arranged on the surface of FTO were grown by seed induction method,and Au nanoparticles were grown on the surface of ZnONRs by hydrothermal method to prepare Au-Zn Ox NRs composite materials,and a new method for glucose electrochemical sensing was constructed based on this material.Research results using SEM,EDX,XRD,XPS and other methods show that Au-ZnONRs are rod-shaped structures with hexagonal cross-sections.The results of electrochemical experiments show that the established new glucose electrochemical sensing method has a linear range of 0.001-15 m M,a sensitivity of 4436?A m M^-1cm^-2 and a detection limit of 0.1?M;it is used for the detection of glucose in the blood.The average standard deviation of the five measurement results is 3.9%.The sensitivity of the sensor is increased by 1.5 times,the detection limit is reduced by3.3 times,and it can be used for the determination of glucose in blood.2.Investigation of electrochemical sensing based on Pt Ni Co nanocompositesThe Pt₅₀Ni₂₅Co₂₅ trimetallic nanocomposite was prepared by a simple one-pot method,and sprayed on the FTO electrode by spray pyrolysis,and a new electrochemical sensing method for catechol and hydroquinone detection was constructed.TEM,EDS and XRD research results show that the octahedral Pt₅₀Ni₂₅Co₂₅ nanocatalyst with a size of 0.35-4 nm has been successfully prepared.The results of electrochemical experiments show that the linear range is 10-900?M,the sensitivity is 1197?A m M^-1cm^-2 and the detection limit is 0.79?M;The linear range of the new phenol electrochemical sensing method is 10-1100?M,the sensitivity is 1035?Am M^-1cm^-2 and the detection limit is 1?M.The detection limit of sensor by using this method is reduced by 1.7 times.The Pt₆₃Ni₃₁Co₆ trimetallic nanocomposite was prepared by the one-pot method,and it was drip-coated on the FTO electrode to construct a new H₂O₂ electrochemical sensing method based on the material.The results of using TEM,XRD and XPS methods show that Pt₆₃Ni₃₁Co₆ of 4-5 nm has been successfully dispersed on the FTO electrode evenly.The results of electrochemical experiments show that the established new H₂O₂ electrochemical sensing method has a linear range of 5-16500?M,a sensitivity of 1374.4?A m M^-1cm^-2 and a detection limit of 0.4?M.Compared with similar sensing methods,the sensitivity of this method is increased by 1.7 times,and the linear range is increased by 19.4 times.