The Application Of Water Soluble Quantum Dots In Tumor Cell Lebeling And Establishment Of Fluorescence Resonance Energy Transfer

In recent years, the application of water soluble quantum dot (QDs) in tumorcells imaging and fluorescence resonance energy transfer (FRET) have been widelyresearched. In this dissertation, different kinds of quantum dots, also with differentmaximum emission wavelengths are used in these two fields. The main contents andresults are as follows:1. CdTe/CdS core/shell quantum dots, which possessed the maximum emissionwavelengths at545nm and600nm, were synthesized by a simple aqueous solutionapproach based on CdTe. The as-prepared CdTe/CdS core/shell QDs with excellentoptical and fluorescence properties were characterized by UV-vis spectra,photoluminescence (PL), XRD and TEM. Two kinds of novle fluorescence probes,CdTe/CdS(545nm)-5-FU and bio-CdTe/CdS(600nm)-TAM, were prepared throughconjugating with anticancer drug5-fluorouracil (5-FU), P-gp inhibiting agentTamoxifen (TAM) and biotin respectively. The mechanism of the conjugations hasalso been investigated. The results of microscopic fluorescence image analysisindicated that bio-CdTe/CdS-TAM conjugates could target to the P-gp. Meanwhile,CdTe/CdS QDs loading the anticancer drug,5-fluorouracil (5-FU), were deliveredinto tumor cells without hindrance. This made the process of inhibition visualization,which will enlarge the application of QDs in imaging and therapy.2．CdTe quantum dots, which the maximum emission wavelengths were at530nm and610nm, were conjugated with two kinds of biomolecules, avidin andbiotin, respectively. The effects of reaction condition, such as pH value, reactiontemperature and reaction molar ratio were also investigated. We have successfullybuilded fluorescence resonance energy transfer (FRET) system using the strongaffinity and high reaction specificity between avidin and biotin. The effect of differentmolar ratios between donor and accepter to the FRET efficiency was researched. Thislaid the foundation for FRET technique applicated in pharmaceutical quantitativeanalysis. Meanwhile, the characterization of the conjugates and FRET system usingHPLC analysis method which is more rapid, accurate and reliable could significantlyincrease the analysis of accuracy and sensitivity.