| Summary: | 碩士 === 國立東華大學 === 光電工程研究所 === 97 === In the first experiment part, we studied nanometer-diamond interaction with bacteria Escherichia coli (for short “E. coli”), and observe the synthetic nanodiamond effect on the bacterium E. coli cell wall using Raman spectroscopy and SEM microscopy. In this study, we found the 5 nm nanodiamond would break bacterium cell wall, but bigger size nanodiamonds (100 nm ~ 1 μm) would not destruct for the bacteria. The nanodiamond destroyed the bacterium cell wall in dependent on the nanodiamond size. We attributed the size dependent effect is caused by the synthetic diamond’s produce method.
In the second experiment part, optical tweezers use to manipulate a single polystyrene bead, nanodiamond-lysozyme complex, and bacteria E. coil in suspension and measured the Raman spectra in vivo at the same time from trapped micro particles. The confocal Raman spectroscopic technique via another usefully tool to visualize the interaction between two systems provide practical spectroscopic information. The usefully experiment involves the applications of the optical trapped designed. One single aggregated nanodiamond (diamond size near 500 nm, size of aggregation ~1 μm) was trapped by the optical tweezers system with 100× oil immersion objective and measured via Laser Tweezers confocal Raman Spectroscopy (LTRS) with 100× normal objective.
Nanodiamond structure was detected at 1332 cm-1 using a 532 nm wavelength laser, less than 15 mW, as excitation source. Study Raman spectra of single aggregated nanodiamond-lysoyme complex interaction with bacterium E. coli, and trapped together in the medium suspension was measured.
The design of laser tweezers system can be used to manuplicate interaction of a single particle, such as polystyrene, bacterium, synthetic nanodiamond or nanodiamond with biological objects.
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