| Summary: | 碩士 === 國立陽明大學 === 醫學工程研究所 === 92 === My research modifies former scholars’ synthesis methods, synthesizing water-soluble CdSe/ZnS (core/shell) quantum dots (QDs). We label collagen fibers with carboxyl quantum dots, whose colors are green and red, emission wavelengths are 524.4 nm and 635 nm, and extinction coefficients are 5.96 × 104 and 5.63 × 105 respectively. Apparent increase in fluorescent intensity indirectly proves that CdSe QDs are overcoated with ZnS to form core/shell structure. We use NMR to analyze carboxyl QDs, and confirm that QDs are successfully carboxylized to become water-soluble. We use carboxyl QDs to label collagen fibers crosslinked by EDC (1-ethyl-3- (3-dimethylaminopropyl) carbodiimide). We use QDs to improve the limitations of fluorescent dyes for cell-labeling because of their short half-time, narrow excitation wavelength and single color emission. From fluorescent intensity decay test, we find that the fluorescent intensity of QD-labeled collagen fibers won’t remarkably decay under successive irradiation. Under transmission electron microscope, we can observe the binding situation of QDs on collagen fibers, and estimate the QDs binding on specific locations. We directly observe QDs on collagen fibers, and discover that there are more QDs labeled on specific locations. Compared with the amino acid sequence of collagen, we see that these locations are densely charged regions and also find the existence of lysine. At last, we mix equal volume of dual-color labeling collagen fibers to form a matrix for cell culture.
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