| Summary: | 碩士 === 國立成功大學 === 化學工程學系 === 103 === This research describes the application of positioning silver nanocubes on different substrates in Surface-Enhanced Raman Scattering (SERS). In the first section, self assembled monolayer(SAM) was used for substrate preparation to immobilize silver nanocubes on silver thin film. In order to knew the thickness effect of the silver thin films and their relationships with plasmonic resonance, silver thin films with different thickness were deposited on two different substrates. It was found that when the thickness of silver thin films reach certain value, their Raman enhancement factors(EF) are almost the same. Same phenomenon was also found on the aluminium substrate with silver thin films. From the result, we could prepare Raman substrate with less time and materials but with same Raman effect. In the second part, substrates were prepared by dropping silver nanocube solution on cheap and easily accessible aluminium substrate. By using three organic compounds R6G, CV and 4-ATP as analytes, silver nanocube solution dropping substrate obtain better Raman performance than the SAM substrate from both detection limit and EF. In order to understand this phenomenon, finite difference time domain method (FDTD) was used to simulate the local electric field intensity distribution. We find that the better performance of this substrate could be derived from the hot spots formation due to aggregation.
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