Enhancement Effect Of CdTe Quantum Dots With Flow Injection Chemiluminescence And Its Application

In recent years, colloidal semiconductor nanocrystals or quantum dots(QDs) have attracted much attention due to their unique size dependent optical and electronic properties, and have been widely used as multicolored photoluminescent probesand biological luminescent labels. Chemiluminescen(CL) analysis has the advantages of high sensitivity, wide linear range,simple instrumentation and no-background scattering light interference, and has been extensively utilized in various fields, such as chip technique, druganalysis, environmental monitoring, clinical diagnose. FIA is that it is a kinetic measurement system in which the system is normally notcompletely mixed and the radial and axial sample concentration profiles are time-dependent functions.In this paper, Cd Te quantum dots were added to several different chemiluminescence system and used into detecting some medical and hormonic compounds. The main research work has the following aspects:1.In alkaline media, Cd Te quantum dots can greatly enhance the chemiluminescence between luminol and hydrogen peroxide, however, dopamine hydrochloride can inhibit the CL of luminol-H2O2-Cd Te QDs system. Based on this characteristic, a simple and convenient method for the determination of dopamine hydrochloride was developed by combination of chemiluminescence and flow-injection analysis technique. The possible CL mechanism was also discussed. Under the optimum conditions, the CL intensity was linear with the concentration of dopamine from 1.2×10-5 to 7.8×10-8 mol/L with a detection limit(S/N=3) of 1.5×10-9 mol/L. The RSD(n=11) for the detection of 2.0%method was sucessfully applied to analyze dopamine in pharmaceutical and human urine.2.In this study, water-soluble Cd Te QDs could the chemiluminescence(CL) emission from the luminol-KMn O4 system in alkaline medium. Moreover, we found that the CL from luminol-KMn O4-Cd Te QDs system is heavy inhibited by the presence of bisphenol A. Based on this inhibition, a novel CL method with a lower detection limit and wider linear range was developed for the determination of bisphenol A. Thus a new flow injection chemiluminescence method was developed for detection bisphenol A. Under the optimum conditions linear dynamic ranges of 8×10-4~6×10-3mg/L to 6×10-3mg/L~0.1mg/L,respectively with corresponding detection limits of 1.68×10-4mg/L.3.Cd Te QDs, as a kind of sensitizer, could enhance the chemiluminescence(CL) emission from the redox reaction of Na2S2O3-Ce(IV) in acidic medium. Under the optimal conditionslinear dynamic ranges of levofloxacin was 4.0×10-8 to 1.0×10-7 g/m L and 1.0×10-7 to 3.5×10-6 g/m L, detection limit was 3.2×10-9g/m L, the RSD was 3.0% for 6.0×10-5 g/m L(n=11).