Electrochemiluminescence Investigations Of Quantum Dots And Ru（bpy）₃²⁺ Immobilized In Quarternary Ammonium Poly（Arylene Ether Sulfone）s

Electrochemiluminescence（ECL）is a kind of light emission during electrochemical reactions,in which high-energy species,generated at the electrodes,undergo a high-energy electron transfer reaction forming an excited state that emits light.The most employed ECL luminophore is ruthenium（II）tris（2,2’-bipyridyl）(Ru（bpy）₃²⁺),and tripropylamine（TPr A）are the most efficient co-reactant when used in combination with Ru（bpy）₃²⁺.However,the application of TPr A co-reactant is restricted due to its toxicity,corrosiveness and volatility.In addition,ruthenium as a rare and noble metals is costly and not conducive to devicization in aqueous solution.Therefore,the development of new co-reactants and the immobilization of Ru（bpy）₃²⁺have been one of the important research direction of ECL.Quantum dots have been studied as coreactant for Ru（bpy）₃²⁺ECL,showing their eligibility as powerful alternatives to TPr A because of its low toxicity and high light stability.Brominated poly（aryl ether sulfone）（PAES-Br）easily reacts with tertiary amine to form poly（arylene ether sulfone）s（QAPAES）,which may be a good carrier for Ru（bpy）₃²⁺and its tertiary amine co-reactants.Basis on the above,this thesis focused on the investigation of ECL behaviors for quantum dots/Ru（bpy）₃²⁺and Ru（bpy）₃²⁺/QAPAES membrane,and the main contents are summarized as follows:1.The ECL behavior of Ru（bpy）₃²⁺/QDs.Carbon dots（CDs）,phosphorus-nitrogen co-doped carbon dots（PN-CQDs）,molybdenum disulfide quantum dots（Mo S₂QDs）were synthesized by bottom-up hydrothermal method,and their ECL behaviors were investigated.The results showed that the three quantum dots had no obvious ECL behavior in aqueous solution,but all of them could enhance the ECL of Ru（bpy）₃²⁺in turn of PN-CQDs>CQDs>Mo S₂ QDs,which had a 28-fold,20-fold,3-fold higher than individual Ru（bpy）₃²⁺respectively.After exploring by UV-vis spectrum,fluorescence spectrum and cyclic voltammetry,it was deduced that as-prepared three quantum dots acted as co-reactants of Ru（bpy）₃²⁺.2.Sequential injection electrochemiluminescent system for determination of L-cysteine based on Ru（bpy）₃²⁺/PN-CQDs.In the sequential injection ECL system,the effects of 17amino acids on the ECL performance of Ru（bpy）₃²⁺/PN-CQDs were investigated.It was found that only L-cysteine had significant inhibition of the ECL of Ru（bpy）₃²⁺/PN-CQDs,and the inhibition degree was linear with L-cysteine concentration in the range of1.0?10^-5～5.0?10^-2mol·L^-1.With the sequential injection ECL system,the sample/regents consumption and analysis time were greatly reduced;the analysis efficiency and reproducibility were also improved.The relative standard deviation of L-cysteine measured by 1.0?10^-4mol·L^-1 is 2.9%（n=11）and the detection limit is 8.4?10^-7mol·L^-1（S/N=3）.The present method was used for the analysis of L-cysteine in urine samples with an acceptable accuracy.3.Preliminary exploration on the ECL performance of Ru（bpy）₃²⁺/MCM-41/QAPAES composite membrane.Firstly,PAES-Br reacted with triethylamine（TEA）to form quaternized PAES（QAPAES）,which was subsequently used to attach Ru（bpy）₃²⁺immobilized on MCM-41.Compared with PAES membrane not being quaternized by TEA,the as-obtained Ru（bpy）₃²⁺/MCM-41/QAPAES membrane modified electrode was clearly observed the strong ECL signal in phosphate buffer owing to QAPAES can not only immobilize Ru（bpy）₃²⁺,but also be co-reacting of Ru（bpy）₃²⁺.