Browsing by Author "Kuo, Chiung-Wen"

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Functionalized silver nanowires for live cell study
(2008-06-05)
Kuo, Chiung-Wen
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Shiu, Jau-Ye
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Wei, Kung Hwa
;
Chen, Peilin
;
材料科學與工程學系
The biocompatibility of the surface-functionalized silver nanowires has been investigated in two cell lines. It was found that the functionalized silver nanowires with 200 nm diameter and length up to a few mu m can be internalized by cells. The cytotoxicity of the silver nanowires was found to depend on their surface modifications. It was also demonstrated that the surface-enhanced Raman scattering (SERS) could be measured on the silver nanowires, which added additional functionality to the silver nanowires.
Monolithic integration of well-ordered nanoporous structures in the microfluidic channels for bioseparation
(2007-08-31)
Kuo, Chiung-Wen
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Shiu, Jau-Ye
;
Wei, Kung Hwa
;
Chen, Peilin
;
材料科學與工程學系
Gel electrophoresis and capillary gel electrophoresis are widely used for the separation of biomolecules. With increasing demand in the miniaturized devices such as lab-on-a-chip, it is necessary to integrate such a separation component into a chip format. Here, we describe a simple approach to fabricate robust three-dimensional periodic porous nanostructures inside the microchannels for the separation of DNA molecules. In our approach, the colloidal crystals were first grown inside the microchannel using evaporation assisted self-assembly process. Then the void spaces among the colloidal crystals were filled with epoxy-based negative tone photoresist (SU-8). UV radiation was used to cure the photoresist at the desired area inside the microchannel. After subsequent development and nanoparticle removal, the well-ordered nanoporous structures inside the microchannel were obtained. Our results indicated that it was possible to construct periodic porous nanostructures inside the microchannels with cavity size around 300 nm and interconnecting pores around 30 nm. The mobility of large DNA molecules with different sizes was measured as a function of the applied electric field in the nanoporous materials. It was also demonstrated that I kilo-base pair (kbp) DNA ladders could be separated in such an integrated system within 10 min under moderate electric field. (c) 2007 Published by Elsevier B.V.
Nanofluidic system for the studies of single DNA molecules
(2008-07-01)
Kuo, Chiung-Wen
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Wei, Kung Hwa
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Lin, Chun-Hsun
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Shiu, Jau-Ye
;
Chen, Peilin
Here, we describe a simple and low-cost lithographic technique to fabricate size-controllable nanopillar arrays inside the microfluidic channels for the studies of single DNA molecules. in this approach, nanosphere lithography has been employed to grow a single layer of well-ordered close-packed colloidal crystals inside the microfluidic channels. The size of the polymeric colloidal nanoparticles could be trimmed by oxygen plasma treatment. These size-trimmed colloidal nanoparticles were then used as the etching mask in a deep etching process. As a result, well-ordered size-controllable nanopillar arrays could be fabricated inside the microfluidic channels. The gap distance between the nanopillars could be tuned between 20 and 80 nm allowing the formation of nanofluidic system where the behavi of of a single lambda-phage DNA molecule has been investigated. It was found that the lambda-phage DNA molecule could be fully stretched in the nanofluidic system formed by nanopillars with 50 nm gap distance at a field of 50 V/cm.
Observation of enhanced cell adhesion and transfection efficiency on superhydrophobic surfaces
(2010)
Shiu, Jau-Ye
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Kuo, Chiung-Wen
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Whang, Wha-Tzong
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Chen, Peilin
;
材料科學與工程學系
It was found that cells attached preferentially on the roughened area of patterned superhydrophobic surfaces allowing the formation of cell microarrays with the advantages of improved cell adhesion, natural separation of colonies and enhanced transfection efficiency.
Studies of surface-modified gold nanowires inside living cells
(2007-12-17)
Kuo, Chiung-Wen
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Lai, Ain-Jung
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Wei, Kung Hwa
;
Chen, Peilin
;
材料科學與工程學系
The cytotoxicity of various surface-functionalized gold nanowires with different aspect ratios is investigated by (3-(4,5-di-me thylthiazol-2-yl)2,5-diphenyltetrazolium bromide) (MTT) assays for two cell lines, fibroblast and HeLa. It is found that functionalized gold nanowires with a diameter of 200 nm and lengths up to a few micrometers can be readily internalized by both types of cells regardless of the type of surface functionalization. However, the cytotoxicity of the gold nanowires is observed to depend on their surface modification. Serum-coated gold nanowires are the least toxic, whereas more than 50% of the cells are damaged in the presence of mercapto-acid-modified gold nanowires even at very low concentrations (10(3) nanowiresmL(-1)). Nanowires with different aspect ratios exhibit the same cytotoxicity within limits of experimental error. However, the uptake efficiency is found to be higher for shorter nanowires as compared to their longer counterparts. Therefore, we conclude that internalized nanowires with high aspect ratios are more toxic to cells than nanowires with low aspect ratios. Positively charged aminothiol-modified gold nanowires are employed to deliver both plasmid DNA and probe molecules into cells without compromising the viability of the cells. The local environment of individual nanowires within the cells is studied by monitoring the fluorescence signal from probe molecules attached to the nanowires.
Surface modified gold nanowires for mammalian cell transfection
(2008-01-16)
Kuo, Chiung-Wen
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Lai, Jun-Jung
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Wei, Kung Hwa
;
Chen, Peilin
;
材料科學與工程學系
Aminothiol modified gold nanowires have been used as vectors for the delivery of plasmid DNA into two different types of mammalian cells: 3T3 and HeLa. It was measured that positively charged gold nanowires with a diameter of 200 nm and a length around 5 mu m were capable of carrying 1 pg of plasmid DNA per nanowire into cells. Compared with other transfection reagents, the gold nanowires exhibited the highest transfection efficiency while almost no cytotoxicity was observed. In addition, it has been shown that individual nanowires can be visualized with sub-micrometer resolution, which may allow the use of functionalized multi-segment nanowires as local probes for the investigation of the microenvironment inside cells.