| Summary: | 碩士 === 國立臺灣大學 === 化學研究所 === 96 === Part A:
An important research direction in nanomaterials synthesis is the expansion from single-component nanoparticles to hybrid nanostructures with discrete domains of different materials arranged in a controlled fashion. Here, we report the synthesis and characterization of binary and ternary hybrid nanocrystals based on spontaneous nucleation and growth of a second and third component onto seed nanoparticle. Multifunctional hybrid nanoparticles combining plasmonic and semiconducting properties which are tunable in size and morphology can be realized, as demonstrated for combinations of Au, CdS, and CdSe. Two classes of hybrid nanoparticles are presented: metal-semiconductor (Au/CdS) and metal-semiconductor-semiconductor (Au/CdSe/CdS) hybrid nanoparticles. In the Au/CdS system, the size of the gold tips can be controlled by the concentration of the starting materials. Using CdS/Au-tip as the seed, CdS nanorod/Au nanorod hybrid nanocrystals can be prepared by a seeding growth approach in the presence of an aqueous miceller template. In the Au/CdSe/CdS system, the Au tip, as a stopper, restrains CdS from necleation on the Au side, then CdS nanorod only grows on the end of CdSe.
Part B:
The single molecule functionalized Au nanoparticles (NPs) were synthesized with the assistance of silica particles. The use of silica particles renders intrinsic advantages that each step along the product formation can be monitored by e.g. transmission electron microscope. The large surface to volume ratio of silica particles leads to a good yield of Au NPs attachment. Here, we demonstrated three methods to prepare gold nanoparticles dimers from the coupling of two singly functionalized-Au NPs (modified with 15-crown-5 ether or single-stranded DNAs (ssDNAs).
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