| Nowadays, Quantum dots (QDs) nanoparticles, because of their unique optical properties such as broader excitation spectrum, narrower emission spectrum and longer lifetime, have attracted many researchers’attentions. Compared with those heavy metal based QDs, carbon quantum dots (CQDs) exhibit many advantages, such as low cytoxicity, good stability, easy preparation, and environmental friendliness. Therefore, more and more attention has been paid to these emerging carbon nanomaterials, including their syntheses, property studies, and applications. Lots of researchers do their best to explore simple and effective methods to synthesize functionalized fluorescent nanomaterials with appropriate size, uniform morphology and good biological compatibility for desired applications. Among them, the surface modification is an important way to obtain perfect functionalized fluorescent nanomaterials, which presents the spectral characteristics of nanomaterials and the functional group of the modifying reagent. At the same time, the combination of fluorescent nanomaterials with chemiluminescence (CL) has attracted substantial interest due to their unique size-dependent optical and electronic properties.In view of this, this dissertation consists of four chapters:Chapter 1 The properties, preparation and application potential of fluorescent nanomaterials, especially quantum dots and carbon quantum dots, are briefly summarized. The surface modification of fluorescent nanomaterials by β-cyclodextrin (P-CD) are introduced. And the application of chemiluminescence (CL) with quantum dot in biology and chemistry is also discussed.Chapter 2 We report a new strategy to obtain an easy-to-prepare and water-soluble β-CD-modified CdTe QDs via layer-by-layer method through the substitution reaction at the C-6 position of mono-6-deoxy-6-(p-tolylsulfonyl)-cyclodextrin (6-TsO-β-CD) by the-NH2 of (3-aminopropyl)triethoxysilane-coated CdTe QDs (APTES/CdTe QDs). The results revealed that β-CD/APTES/CdTe QDs simultaneously possessed unique optical properties of QDs and excellent molecules recognition ability of β-CD through combining their individual distinct advantages. The salient advantages of the present work were as follows:(1) the experimental chemicals and reagents used were inexpensive and straightforward; (2) the preparation of APTES/CdTe QDs were performed by mechanically agitating in the ethanol phase instead of refluxing in toluene, so reducing the pollution to environment; (3) P-CD was easily grafted onto the surface of APTES/CdTe QDs after being only pretreated by simple sulfonylation.Chapter 3 A facile and flexible procedure for the preparation of β-CD modified carbon quantum dots (β-CD-CQDs) was successfully developed for the first time, and various techniques were utilized to characterize the multifunctional nanoparticles. The surface-immobilized β-CDs still retained the capability of engaging molecular recognition at CQDs surfaces in aqueous solutions. In addition, the synthesized β-CD-CQDs showed selective response to Fe(II) and Fe(III) after couping with o-phenanthroline.Chapter 4 In this work, we explored the effect of CdTe QDs obtained at different reflux time on the chemiluminescence (CL) intensity of the luminol-H2O2 reaction as a model system. It was found that a stronger CL signal was observed when CdTe QDs was added to luminol-H2O2 mixed solution. However, L-ascorbic acid can inhibit the CL intensity of luminol-H2O2, which is dependent on L-ascorbic acid concentration. Based on this phenomenon, a new, simple, sensitive and selective method is proposed for the determination of L-ascorbic acid in common Vitamin C tablets. The work will be helpful for the further development of fluorescent nanomaterials to the applications field of chemiluminescence. |
PDF Full Text Request