Application Of Metal Nanocomposite Modified Electrochemical Sensors In Disease Markers And Pharmaceuticals

In recent years,the use of electrochemical methods to detect disease markers and pharmaceuticals has become a hot spot in the field of electrochemical research.It is well known that disease markers have many indicators,mainly composed of small molecule disease markers and large molecule disease markers(including nucleic acids and proteins,Sugar and lipid disease markers),the abnormal content of these indicators in the human body is usually a sign of disease.Antibiotic pharmaceuticals can inhibit the growth of bacteria or kill bacteria.Because antibiotics and their metabolites can penetrate into surface water and groundwater,the residues of antibiotics pollute the environment,which seriously affects the ecological balance and human health.Therefore,there is an urgent need to develop a highly sensitive method for detecting disease markers and pharmaceuticals contents in biological samples.Metal nanocomposite materials are composed of two or more nanomaterials.They have the advantages of good electrocatalytic performance and can exert synergistic effects.They can be used to form electrochemical sensors with excellent performance.Therefore,this paper mainly studies the application of metal nanocomposite modified electrochemical sensors in disease markers and pharmaceuticals.The specific research contents are as follows:1.Design an electrochemical sensing platform(GR-SWNT-Ce-Cu-Tween 20 / GCE)based on a metal nanocomposite modified by electrodeposition of cerium and copper on graphene and single-walled carbon nanotubes for high sensitivity Simultaneous determination of dopamine(DA),uric acid(UA)and glucose(Glu).Scanning electron microscopy(SEM)and X-ray diffraction(XRD)were used to characterize the modifiers.Cyclic voltammetry(CV),differential pulse voltammetry(DPV),and electrochemical impedance spectroscopy(EIS)explores the electrochemical behavior of sensing platforms.The results show that in the coexistence system of DA,UA and Glu,under the optimal conditions,three clear and well-separated voltammetric peaks are obtained by DPV method,with linear ranges of 0.1-100 ?M,0.08-100 ?M,and 1-3000 ?M,respectively.The detection limits(S / N = 3)are 0.0072 ?M,0.0063 ?M,and 0.095 ?M,respectively.It has been successfully used in the determination of DA,UA and Glu in diabetic human serum with good results.2.Gold nanoparticles(Au NPs)were prepared by the trisodium citrate reduction method,and were compounded with chitosan(CS)and sodium dodecylbenzenesulfonate(SDBS).A new electrochemical sensor for the simultaneous detection of norepinephrine and L-cysteine was constructed.The electrochemical sensor constructed by CS-Au NPs-SDBS / GCE has good electrochemical response and noble electrocatalytic performance to norepinephrine and L-cysteine.Under the optimal experimental conditions,it is compatible with a bare glass carbon electrode(GCE)Compared with CS-Au NPs / GCE,CS-Au NPs-SDBS / GCE showed significant electrocatalytic activity for norepinephrine and L-cysteine oxidation.The linear ranges were 0.08 to 100 ?M and 0.2 to 400 ?M,respectively,and the detection limits were 0.0034 ?M and 0.052 ?M(S / N = 3).In addition,research was conducted on the interference detection of norepinephrine and L-cysteine.The results showed that norepinephrine and L-cysteine have strong anti-interference ability,and successfully achieved the determination of norepinephrine and L-cysteine in human serum samples.3.Use ?-cyclodextrin(?-CD)with good electrical conductivity and metal platinum nanoparticles(Pt NPs)with excellent biocompatibility and load capacity to construct highly sensitive electrochemical sensors(?-CD-Pt NPs-SDS / GCE)and applied to detect homocysteine.The morphological structure of Pt NPs-?-CD was characterized by SEM and other methods.The homocysteine was detected by the DPV method.The results showed that the constructed electrochemical sensor had a low detection limit,high sensitivity,and good reproducibility and stability.In addition,homocysteine has a good linear range from 0.8 to 6000 ?M,and the detection limit is 0.052 ?M(S / N = 3).The prepared electrochemical sensor was successfully used to detect homocysteine in human serum.4.Designed based on multi-layer graphene(GR)and single-walled carbon nanotubes(SWCNT)as the base material of glassy carbon electrodes,compounded with cerium nanomaterials(Ce NPs)with unique electrocatalytic properties and electron transfer capabilities to build GR-SWCNT-Ce NPs-SDBS / GCE The chemical sensing platform shows significant electrocatalytic activity for the oxidation reaction of oxytetracycline,chloramphenicol,metronidazole,rifampicin and ciprofloxacin,and the linear ranges are 0.6-100 ?M,0.2-80 ?M,0.8-20 ?M,0.08-20 ?M and 0.4-100 ?M,the detection limits(S / N = 3)were 0.036 ?M,0.011 ?M,0.23 ?M,0.016 ?M and 0.089 ?M.The results show that the electrochemical sensors constructed with metal nanocomposites have a wider linear range,higher sensitivity,lower detection limits,good reproducibility and stability,and strong anti-interference ability,and successfully achieve biological Determination of five antibiotics in the sample.