Research On New Analytical Detection Method Based On Quantum Molybdenum Disulfide Quantum Dots

Electrochemiluminescence(ECL),as a fast,simple,high sensitivity,easy to operate and good stability analysis technology,has been widely concerned by most researchers.ECL analysis method of this paper is based on Ru(bpy)32+study of the background,the research of the current hot new MoS2 nanomaterials quantum dots,the ECL performance and potential and the interaction between other ECL body,at the same time with the analysis of ECL analysis and fluorescence quenching method using MoS2 quantum dots detecting drugs of small molecules,finally obtained the very good detection effect,has potential application value.1.The introduction.In this section,the principles of ECL analysis and photoluminescence analysis are briefly introduced,and the synthesis methods and applications of MoS2 quantum dots,as well as the research progress in ECL and photoluminescence analysis are described in detail;At the same time,the research status of ECL of Ru(bpy)32+ in recent years is introduced.Finally,the significance and main research contents of this thesis are described.2.The MoS2 quantum dots were characterized by TEM,HRTEM and XPS.The synthesized MoS2 quantum dots were uniform in size with an average particle size of about 2.7 nm.The ECL signal of MoS2 quantum dots itself is very weak,but it can greatly enhance the ECL of potassium persulfate.Moreover,the ECL intensity of MoS2 quantum dots modified electrode is greatly enhanced after activation in potassium persulfate for a certain period of time.After adding folic acid into the system,the ECL signal decreased sharply,based on which folic acid was detected.3.Fluorescence quenching of MoS2 quantum dots is used for the detection of folic acid.In recent years,MoS2 quantum dots have attracted extensive attention in the detection of small molecules.However,so far,no literature has reported folic acid(FA)detection based on MoS2 QDs.In this paper,a simple,rapid and selective fluorescence analysis method was established.The fluorescence quenching of MoS2 quantum dots was rapid and obvious after the addition of FA to the synthesized molybdenum disulfide quantum dots,and the fluorescence quenching degree increased with the increase of FA concentration.The fluorescence intensity decreased linearly with the increase of FA concentration between 1.0×10-7 mol/L to 1.25×10-4 mol/L.The mechanism of fluorescence quenching is studied and the results show that the process is static quenching.The method was used to determine FA in commercial folic acid tablets.4.Bipyridine ruthenium-triethylamine ECL method was used to determine L-cysteine.L-cysteine can effectively reduce the ECL intensity of Bipyridine ruthenium-triethylamine system.The effect of dissolved oxygen on the ECL of the system was studied.Under the conditions of oxygen removal and optima]experimental conditions,L-cysteine concentration within the range of 4.0×10-5 to 2.0×10-3 mol/L showed a linear relationship with its ECL intensity,and the linear equation 1=12283.3647-4285.5906C(10-3 mol/L),and the detection limit of the method was 8.0×10-6 mol/L(S/N=3).The method was applied to the determination of L-cysteine in yogurt.