Single-waveband Electrochemiluminescence Of CsPbBr₃@Ag₂S Nanocrystal Hybrids And Ag-Ga-In-S Quantum Dots

Electrochemiluminescence(ECL),a technology combining electrochemistry and chemiluminescence.It has both the advantages of high sensitivity of chemiluminescence.and potential controllability of electrochemistry.Based on these characteristics,it has been widely used in the areas of biochemical analysis and clinical diagnosis.The traditional ECL sensor application research is based on single-component analysis.The development of single-waveband ECL systems with different radiation bands has important academic value for ECL multi-component analysis based on spectrum(or color)recognition mode.Based on the promotion of basic research on perovskite quantum dots for luminescence applications and the development of low-toxic multi-element quantum dot ECL substances,the ECL properties of perovskite quantum dots and multiple low-toxic quantum dots are investigated in this thesis The single-waveband ECL was obtained in the green and near-infrared regions,enriching the types of ECL reaction systems which perform the band-resolved ECL analysis and research The main contents are outlined as follows:1.The preparation of the water stable CsPbBr3@Ag2S nanocomposite and its monochrome ECL radiation characteristics.Nanocomposites of CsPbBr3@Ag2S were prepared via decomposing Ag(DDTC)directly in the CsPbBr3 NCs solution.The photoluminescence(PL)and ECL radiation of CsPbBr3@Ag2S nanocomposite are obviously superior to those of CsPbBr3 NCs,and the single-waveband radiation properties of CsPbBr3 NCs are retained.The electrons or holes injected into the Ag2S segment of the CsPbBr3@Ag2S nanocomposite can be transferred to the counterpart CsPbBr3 segment to enhance the radiative charge transfer occurred within CsPbBr3 segment under electrochemical excitation conditions.These results can provide technical support for the aqueous ECL application research of NCs,and the design of novel stable and tunable optoelectronic devices.A strategy is developed to effectively improve the aqueous stability and ECL performance of perovskite nanometrials.2.The single-waveband ECL of water-soluble Ag-Ga-In-S(AGIS)QDs and its biochemical sensing were investigated.The water-soluble AGIS and Ag-In-S(AIS)QDs were prepared by adjusting raw material.It was shown that AGIS QDs not only retained the morphology,size,phase and water-solubility characteristics of AIS QDs,but also exhibited significant enhancements in PL and single-waveband ECL,and obvious blue shift in emission wavelength.The photo luminescent quantum yield increased from 4%to 10%.The single-waveband near-infrared ECL is blue shifted from 772 nm in AIS QDs to 745 nm in AGIS QDs,and the radiation intensity is doubled.Relevant results demonstrate that the partial replacement of In3+ by Ga3+will widen the band gap of quantum dots and reduce the surface defects of quantum dots.Therefore,the application value in biochemical analysis can be improved.The sandwich ECL sensor was constructed with triethylamine as the anodic coreactant and AGIS QDs as the signal tag for sensitive detection of prostate specific antigen with the detection range 0.05 pg/mL?1.0 ng/mL and the low detection limit of 0.01 pg/mL.The results show that the multiple quantum dots provide a new direction for the development of a new ECL reaction system with low-toxic elements.