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Investigation Of Design And Application Of Several Novel Types Of Optical Molecular Chemosensors

Posted on:2006-11-17Degree:MasterType:Thesis
Country:ChinaCandidate:J L ChenFull Text:PDF
GTID:2168360155450981Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
Optical molecular chemosensors (OMCS) has emerged in the field of analytical chemistry as an application form on the research on molecular recognition, Research on OMCS has been one of the current scientific fronts due to its unique contributions in probing composition, structure or evolution of environmental of microbiological systems. Along this line, the research on several novel types of optical molecular chemosensors was conducted and a series of optical molecular chemosensors has been developed in this dissertation based on the traditional design strategies of optical chemosensors, in which a wide range of chemical substances including anion, metal cations, acidity pH was involved as analytical targets. This dissertation consist of seven chapters summarized in the following: In chapter1, first a general introduction to the basic conception and research status quo, development trend of OMCS was presented. Second, we investigate and summarized the relative research reports and cultures about OMCS. Finally, based on the concerning updated development and our experiment institutions, the research proposal for this dissertation was presented. In the chapter 2, the reagents, apparatus and synthesis of some probes compounds by this dissertation were described. In chapter 3, the common principle of the protection and de-protection in the organic synthesis reaction was conducted to design and application of OMCS. First, a cyanine dye involving hydroxyl as colorimetric sensing signal group, we designed and synthesized a novel colorimetric sensor for fluoride ion. The proposed method has been successfully applied for determination for fluoride in local rainwater samples. This design offers a new strategy on sensors for small gas molecules and anions in aqueous. In chapter 4, two types of "differential optical molecular chemosensors"("DOMCS") for iron (II) were described. The most familiar conception on redox reaction was conducted to DOMCS design. As well known, stable nitroxide radical is a series of quenchers for aromatic fluorophore by single excitation state. Two kinds of DMOCS were designed and synthesized by covalently linking TEMPO to pyrene fluorophore with long lifetime, high fluorescence quantum yield via ester bond. In chapter 5, CdS QDs funtionalized with L-cysteine was synthesized by one step. These QDs only exhibited deep trap emission (defection emission). Based on the different and sensitive optical responded to heavy and transition metal (HTM), a basic interaction between HTM and QDS DMCS was studied. These experiment found was hoped to be HTM sensor for application in real tissue such as cell. In chapter 6, CdS QDs were synthesized with one new mean. These QDs exhibited two different optical signals: scattering emission and deep trap emission in visible region. Based on the optical signals different dependence on the pH value of buffer solution system. Then, the wavelength-ratiometric method for pH sensing in the range of cytosolic pH of cell 6.8-7.4 was proposed. The mechanism of the CdS QDs optical dependence on pH was studied. In chapter 7, the characteristic and innovation of the dissertation were given.
Keywords/Search Tags:Molecular Chemosensors, Colorimetric sensor, Spin probe, quantum dots
PDF Full Text Request
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