Preparation Of Carbon Based Metal Composites And Their Application In Electrochemical Sensing

In this paper,we used the carbon material as subatrate,and then the metal materials were modified on the surface of carbon subatrate.The prepared carbon based metal composites have the advantages of large specific surface area,good electrical conductivity,high mechanical properties,good electron transfer performance and good catalytic performance.At the same time,the carbon based metal composites were used in the field of electrochemical sensing.The sensor based on carbon based metal composites can effectively achieve the monitoring of the food and drug safety issues.An electrochemical sensor of acetaminophen based on poly diallyl dimethyl ammonium chloride?PDDA?-functionalized reduced graphene loaded Al₂O₃-Au nanoparticles coated onto glassy carbon electrode?Al₂O₃-Au/PDDA/rGO/GCE?were prepared.The as-prepared electrode modified materials were characterized by scanning electron microscopy,X-ray powder diffraction,Fourier transform infrared spectroscopy.The electrocatalytic performances of modified glassy carbon electrode were investigated by cyclic voltammetry and differential pulse voltammetry.The research showed that modified glassy carbon electrode having good electrochemical performance,attributing to the synergetic effect comes from the special nanocomposite structure and physicochemical properties of Al₂O₃-Au nanoparticles and graphene.The low detection limit of 6 nM?S/N = 3?and the wide linear detection range from 0.02 ?M to 200 ?M?R2 = 0.9970?was obtained.The preparation of sensor was successfully applied to detection of acetaminophen in commercial pharmaceutical pills.A highly efficient and sensitive electrochemical sensor for epinephrine based on reduced graphene and multi-walled carbon nanotube hybrid nanocomposites loaded TiO₂-Au nano-clusters modified glassy carbon electrode was developed.The morphology of the nanocomposite and the electrochemical properties of the sensor were characterized by Raman spectra,X-ray powder diffraction,scanning electron microscopy,Energy dispersive X-ray spectra,fourier transform infrared spectroscopy,electrochemical impedance spectroscopy and cyclic voltammetry,respectively.Carbon nanomaterials were widely used in sensing due to its large electroactive surface area,fast electron transport and strong adsorption capacity.Meanwhile,TiO₂-Au nano-clusters could accelerate the electron transfer,increase reactive site and extend electrochemical response window.The nanocomposite could greatly enhance the response sensitivity and decrease the overpotential.The resulting sensor showed an excellent electrocatalytic activity towards epinephrine.Under the optimum conditions,Differential pulse voltammetry was employed to detect ultra-trace amounts of epinephrine.The result of a wide linear range of 1.0-300 nM and limited of detection 0.34 nM?S/N = 3?were obtained.The nanocomposite film sensor was successfully used to accurately detect the content of epinephrine in practical samples.A highly effective electrochemical sensor was developed for highly sensitive detection of bisphenol A,based on gold nanoparticles coated 1-butyl-3-methyl imidazole hydrobromide functionalized graphene oxide and carboxylic carbon nanotubes composite film modified glassy carbon electrode.The negatively charged carboxylic acid functionalized carbon nanotubes and AuNPs can be adsorbed on the positively charged GO-IL composite film by electrostatic adsorption.The GO-IL-CNT-Au NPs hybrid nanocomposites with excellent conductivity were obtained conveniently by introducing IL,CNT,AuNPs with good conductivity materials.Seeing that there is a good synergistic effect between materials in enhancing preconcentration efficiency of bisphenol A and accelerating electron transfer rate at electrode/electrolyte interface,the hybrid nanocomposites fabricated electrochemical sensor possess fast,stable and sensitive detection performance for trace amounts of bisphenol A.Differential pulse voltammetry was used for the determination of BPA,and a much wider linear dynamic range of bisphenol A determination was found between 5 nM and 100 nM.The limit of detection was found down to 1.5 n M based on S/N = 3.The modified electrode was successfully employed to detect of bisphenol A extracting from plastic water bottle and milk carton.A simple and sensitive electrochemical sensor for detection of metformin has been developed based ionic liquid functionalized carboxylic carbon nanotubes supported copper nanoparticles?MWCNT-IL-CuNPs?coated onto glassy carbon electrode.The prepared carboxylic carbon nanotubes,ionic liquid functionalized carboxylic carbon nanotubes and MWCNT-IL-CuNPs were detailedly characterized by scanning electron microscopy;X-ray diffraction and Fourier transform infrared spectroscopy.The electrochemical properties of the hybrid nanomaterials were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy.Meanwhile,the as-proposed sensor toward the response of metformin was analyzed via cyclic voltammetry and differential pulse voltammetry.The resulting sensor showed an excellent electrocatalytic activity towards metformin.Under the optimum conditions,Differential pulse voltammetry was employed to determine the content of metformin,for which a wide linear range of 3 nM-50 ?M and the limited of detection 1.0 nM?S/N = 3?were obtained.The proposed sensor exhibited excellent accuracy and precision and the relative standard deviation was less than 5%.The high sensitive sensor was successfully used for accurate determination the content of metformin in practical samples.