Research And Application Of Drug Sensor Based On Electrochemiluminescence

ObjectiveAcetaminophen（AP）and sulfamethoxazole（SMZ）are commonly drugs used in clinical.Due to the wide applications,these two compounds have been found in sewage treatment plants and groundwater.Considering the impact of drug residues on environmental safety,it is very important to find a sensitive,simple,accurate and reliable analytical method to detect them.At present,the commonly used detection methods basically meet the requirements of feasibility and sensitivity of drug analysis,but many detection methods require tedious sample pretreatment process,complicated and expensive operation instruments and long analysis time.These disadvantages are not desirable in quality control.The electrochemiluminescence（ECL）drug sensor overcomes the above obstacles and has the advantages of high selectivity,fast response,and simple operation.It eliminates the sample pretreatment process and can modify the influencing factors such as buffer solution type and p H value,which greatly improves the sensitivity of the detector.Boron nitride quantum dots（BNQDs）are nanomaterials with size dependent optical properties,which have attracted the attention of a large number of researchers in recent years.When the size of boron nitride（BN）powder were reduced to the quantum dots level,the fluorescence spectrum showed that they had the characteristic of fluorescence emission that changed with the excitation wavelength,and the mixed solution of BNQDs and tris（2,2’-bipyridine）dichlororuthenium（II）(Ru（bpy）₃²⁺)showed excellent ECL sensitization.Therefore,it has a significant application prospect in the field of ECL sensor.At present,most of the ECL sensors based on Ru（bpy）₃²⁺are performed in aqueous media,which limits their application in water-insoluble substances.In this subject,the non-aqueous ECL sensor prepared by using N-methyl pyrrolidone（NMP）as the co-reactant of Ru（bpy）₃²⁺was used for the first time.MethodsBNQDs were prepared by continuously ultrasounically stripping the boron nitride（BN）powder dispersing in N,N-dimethylformamide（DMF）organic solution and then further heating and shearing in a high-pressure kettle.After dialysis,BNQDs were uniformly distributed in deionized water.Atomic force microscope（AFM）was used to study the surface morphology and particle size of BNQDs obtained under different preparation conditions.The ultraviolet-visible spectrophotometer（UV-Vis）and fluorescence spectrophotometer were used to study the optical properties of BNQDs and the Ru（bpy）₃²⁺/NMP luminescence system.The cyclic voltammetry（CV）and ECL analyzer were used to study the ECL process of Ru（bpy）₃²⁺/BNQDs and Ru（bpy）₃²⁺/NMP luminescence systems and the experimental factors affecting the intensity of ECL signals,as well as the applications of above two ECL drug sensors to detect AP and SMZ.Results（1）The prepared BNQDs have uniform distribution and consistent size.The AFM height curve shows that the height of BNQDs range from 1nm to 2nm and the average height is 1.56nm,which meets the size requirement of the quantum dots.The characteristic UV absorption peak of BNQDs solution is observed at300nm.Two sharp fluorescence excitation peaks are observed at the wavelengths of 210nm and 290nm,and the Stokes shifts are 165nm and 110nm,respectively.The fluorescence intensity and the position of the emission peak of BNQDs change with the increase of the excitation wavelength,and the maximum emission peak appear at 400nm.（2）The ECL drug sensor prepared by BNQDs as Ru（bpy）₃²⁺co-reactant has good stability and application prospect.In the buffer solution at p H8.0,the ECL signal quenching intensity（ΔI）of Ru（bpy）₃²⁺/BNQDs-ECL drug sensor has a good linear relationship with the natural logarithm concentration（ln C）of AP in the concentration range of 1x10^-6mol/L–1x10^-3mol/L.The limit of detection（LOD）is 4.8x10^-8mol/L.（3）The Ru（bpy）₃²⁺/NMP-ECL drug sensor prepared by using organic solvent NMP as the co-reactant of Ru（bpy）₃²⁺has a good application prospect.When the concentration range of SMZ is 1x10^-7mol/L–1x10^-5mol/L,the quenching intensity（ΔI）of Ru（bpy）₃²⁺/NMP-ECL drug sensor ECL signal has a linear relationship with the logarithm（log C）of SMZ concentration,and the limit of detection（LOD）is as low as 3.33x10^-9mol/L.ConclusionsThe BNQDs were prepared by ultrasonic-solvothermal method,and the stable BNQDs dispersed in deionized water were obtained by dialysis.BNQDs can be used as the co-reactant of Ru（bpy）₃²⁺to enhance the anode ECL signal of Ru（bpy）₃²⁺.This Ru（bpy）₃²⁺/BNQDs-ECL sensor has strong ECL signal and high stability.Based on the energy transfer quenching effect between the excited state of Ru（bpy）₃^2+*and the oxidation product of AP,an AP-Ru（bpy）₃²⁺/BNQDs-ECL drug sensor was designed.NMP can not only acts as the solvent of Ru（bpy）₃²⁺/NMP-ECL system,but also as the co-reactant of Ru（bpy）₃²⁺to enhance the ECL signal of Ru（bpy）₃²⁺.On this basis,a simple non-aqueous Ru（bpy）₃²⁺/NMP-ECL sensor with strong ECL signal was established.Based on the quenching effect between the excited states of Ru（bpy）₃^2+*and the oxidized product of SMZ,an SMZ-Ru（bpy）₃²⁺/NMP-ECL drug sensor was designed,which opened up a new prospect for the rapid and sensitive detection of SMZ.