Study On The Luminescence Properties Of Conjugated Polymer Dots And Their Analytical Applications

Electrochemiluminescence or electrogenerate chemiluminescence(ECL)is a new luminescence analytical technique which combines electrochemistry and chemiluminescence method.ECL has shown many advantages such as high sensitivity,wide linear response range,high selectivity,and easy controllability.As so far,the ECL luminophors generally include widely applied ruthenium coordination compounds,heavy metal-based quantum dots and carbon quantum dots.Recently emerging conjugated polymer dots(CP-dots)exhibit highly intensive fluorescence,good photostability,low cytotoxicity,and excellent biocompatibility,thus they have been widely researched by many scientists.However,the previously reported CP-dots almost don't have ECL activity in the aqueous phase,so it's very difficult to apply CP-dots in sensors.In this thesis,research was focused on the preparation of functionalized CP-dots,investigation of their ECL and fluorescence properties,discussion of related ECL mechanisms,and applications of CP-dots in the field of analysis and testing.The thesis includes four chapters as follow.In chapter 1,the literatures related to ECL and conjugated polymer dots were briefly reviewed,introductions on ECL principles,the advances in ECL,the syntheses and applications of CP-dots were described in details.What's more,the significance and research purposes of this thesis work were mentioned.In chapter 2,Triton X-100 capped MEH-PPV CP-dots were synthesized by reprecipitation procedure,the morphology and spectra of MEH-PPV CP-dots were characterized separately,and their electrochemistry and ECL property were researched.It was found that MEH-PPV CP-dots had multi-channel ECL activities,including annihilation ECL,anodic ECL and cathodic ECL,and the CP-dots showed the strongest ECL on the GC electrode.Finally,MEH-PPV CP-dots/TPrA ECL sensing system was applied in the detection of H2O2,with the detection limit of 9.96×10-7mol/L(S/N=3).In chapter 3,the hydrophilic PPE CP-dots capped by Triton X-100 were synthesized,and UV-vis,fluorescence and ECL properties were studied.The annihilation ECL responses under pulse potentials and coreactant ECL reaction with TPrA were investigated.The influence of dissolved oxygen in electrolyte on the annihilation ECL and coreactant ECL was discussed separately.According to electrochemical,optical spectrum and ECL results of PPE CP-dots,a possible ECL mechanism was discussed and proposed.In chapter 4,F-127 micelle and silica co-protected conjugated polymer nanoparticles(MEH-PPV-F127-SiO2-NH2 NPs)were synthesized,and UV-Vis,the fluorescence properties were studied in details.A new method for the detection of mercury ion was established based on that the fluorescence of MEH-PPV-F127-SiO2-NH2 NPs could be selectively quenched by mercury ion,with a linear range from 1.0×10-6?1.0×10-4 mol/L,and a detection limit of 7.9×10-7 mol/L(S/N=3).