Carbon Tube/dye Modified Glassy Carbon Electrodes And Its Application For Determination Of Antibiotics Contaminants In Water

As representatives of the quinolones and sulfonamides,ciprofloxacin hydrochloride(CPLX)and sulfonamide(SA),respectively,were two major antibiotics.Excessive use of these drugs will make the environment contaminated,which will also lead to the residues of these drugs in food,and ultimately get into human body through the food chain,endangering human health.In this paper,as modifiers,multi walled carbon nanotubes(MWNTs),methyl red(MR)and methylene blue(MB)were modified on the surface of glassy carbon electrode by chemical and electrochemical methods,and a variety of modified electrodes were prepared.The electrochemical detection methods of ciprofloxacin hydrochloride and sulfanilamide were studied.The electrochemical behavior of CPLX and SA on the modified electrodes were studied and experimental conditions about electrochemical detection were researched.The main results of this paper were as follows:1.MWNTs/GCE,PMR/GCE,PMR/MWNTs/GCE,PMB/GCE and PMB/MWNTs/GCE,five kinds of modified electrodes were prepared.The optimum amount was discussed.For MWNTs/GCE electrode,the best modification amount was 10 μL;for PMR/GCE and PMB/GCE,the best number of polymerization cycles were 10 laps and 15 laps respectively.The SEM results showed different electrodes had different surface morphology.2.The electrochemical behaviors of CPLX on MWNTs/GCE,PMR/GCE and PMR/MWNTs/GCE were investigated by cyclic voltammetry(CV)and linear sweep voltammetry(LSV).Many experimental parameters,such as scan rate,electrolyte solution type,pH of electrolyte solution,enrichmentpotential and time were optimized.The results showed PMR/MWNTs/GCE had the most obvious catalytic effect for CPLX.In the range of 8×10-6-1×10-3mol/L,the CPLX oxidation peak current and the concentration showed a good linear relationship.And the regression equation with the correlation coefficient of 0.9936 was Ip(mA)=4.6381C(mol/L)+0.2678.The detection limit was3.0×10-7 mol/L.3.As working electrodes,MWNTs/GCE,PMB/GCE and PMB/MWNTs/GCE were used to investigate the electrochemical behavior of SA by CV and LSV,respectively.The results showed that the three kinds of modified electrodes had obvious electrochemical response to SA,especially the PMB/MWNTs/GCE had the best effect.In the range of 8.0×10-6mol/L-6.0×10-4 mol/L,the regression equation with the correlation coefficient of 0.9967 was Ip(μA)=0.9339C(μmol/L)+71.7152.The detection limit was2.0×10-8 mol/L.