Investigation Toward0D/1D Fast Transformation Of CdTe Nanostructures And Fluorescence Polarization Sensing

In recent years, inorganic luminescent nano-materials, due to their uniqueperformance, have been received the widespread attention. Because of difference inthe quantum confined effect, zero-dimensional (0D) and one-dimensional (1D)luminescence materials with the same composition have different optics and physicsproperties. Specifically, some1D nanorods (NRs) show a large extent of polarization,0D nanoparticles (NPs) show much smaller extents of polarization. Nevertheless, howto realize the transformation between0D and1D nano-materials? In this dissertation,based on the literatures about dimension transformation of nano-materials, theconditions and rules about0D/1D fast transformation of CdTe nanostructures havebeen systematically investigated, and in-situ label-free fluorescence polarization (FP)sensing systems have been constructed based on significant difference in fluorescenceproperties of0D/1D nano-materials. Dissertation is divided into six chapters, thespecific content is as follows:In chapter1, first, the properties and applications of nano-materials wereintroduced concisely. Then, the concepts, natures, synthetic methods and applicationsof0D quantum dots and1D nano-materials were summarized. Next,0D/1Dtransformation of nano-materials and FP sensing theory with application progresswere elaborated. Finally, the ideas of dissertation were presented.In chapter2, based on the literature with slight modification, water-solution0DCdTe nanocrystals (NCs) and1D CdTe NRs were synthesized and characterized.In chapter3, the experimental phenomena, about the transformation from1DCdTe NRs to0D CdTe NPs etched by Eu(III) ions, were studied deeply. The reactionmechanism of1D CdTe NRs to0D CdTe NPs was explored by contrast experimentsand thermodynamic theory.In chapter4, a novel label-free FP sensing system for the determination of singlerare earth metal Eu(III) ions was developed based on the changes of FP signals duringthe above transformation process under the premise of controlling transformationexperimental conditions from1D CdTe NRs into0D CdTe NPs. In chapter5, the experimental phenomena and intermediate process, about thetransformation from0D CdTe NCs to1D CdTe NRs with high crystallination inducedby rare earth metal Eu(III) ions, were investigated particularly. The transformationconditions and mechanism, the role of Eu(III) ions and peculiarity of the crystallinestructure of as-induced1D CdTe NRs were explored in detail.In chapter6, a novel label-free FP method for the determination ofpyrophosphate (PPi) was developed based on the FP signal changes resulted from fasttransformation of Eu(III)-induced1D CdTe NRs to0D CdTe NCs triggered byaddition of PPi.Finally, the full text of dissertation were summarized and the follow-up researchideas were proposed.