Browsing by Author "Hung, Cheng-Hsiung"

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Accurate real-time sensing tip for aqueous NO with optical fibers embedded in active hydrogel waveguide
(2018-02-01)
Chung, Chieh-Wen
;
Tsai, May-Jywan
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Lin, Peng-Wei
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Huang, Ding-Wen
;
Wang, Kuan-Hsun
A NO sensing tip is made by inserting two parallel optical fibers inside a poly 2-hydroxyethyl methacrylate (PolyHEMA) hydrogel waveguide mixed with the probe molecule 1, 2-Diaminoanthraquinone (DAQ). There is a length difference of 1 mm between the two fibers, and the light has to propagate through the difference from the short fiber to the long fiber. The total cross section area of the active hydrogel waveguide embedded with the fibers is only 3mm x 1.2 mm. For practical use the tip is housed in a needle for mechanical protection and the sensing tip is able to detect aqueous NO concentration around 1 mu M with time resolution about 5 minutes. Such a sensing tip can be used to monitor the medical conditions inside the brain after a stroke or a brain injury. (C) 2018 Author(s).
Novel poly-silicon nanowire field effect transistor for biosensing application
(2009-01-01)
Hsiao, Cheng-Yun
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Lin, Chih-Heng
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Hung, Cheng-Hsiung
;
Su, Chun-Jung
;
Lo, Yen-Ren
A simple and low-cost method to fabricate poly-silicon nanowire field effect transistor (poly-Si NW FET) for biosensing application was demonstrated. The poly-silicon nanowire (poly-Si NW) channel was fabricated by employing the poly-silicon (poly-Si) sidewall spacer technique, which approach was comparable with current commercial semiconductor process and forsaken expensive E-beam lithography tools. The electronic properties of the poly-Si NW FET in aqueous solution were found to be similar to those of single-crystal silicon nanowire held effect transistors reported in the literature. A model biotin and avidin/streptavidin sensing system was used to demonstrate the biosensing capacity of poly-Si NW FET. The changes Of ID-VG curves were consistent with an n-type FET affected by a nearby negatively (streptavidin) and positively (avidin) charged molecules, respectively. Specific electric changes were observed for streptavidin and avidin sensing when nanowire surface of poly-Si NW FET was modified with biotin and streptavidin at sub pM to nM range could be distinguished. With its excellent electric properties and the potential for mass commercial production, poly-Si NW FET can be a very useful transducer for a variety of biosensing applications. (C) 2008 Elsevier B.V. All rights reserved.
Origin of hysteresis in current-voltage characteristics of polycrystalline silicon thin-film transistors
(2009-03-01)
Lin, Horng-Chih
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Hung, Cheng-Hsiung
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Chen, Wei-Chen
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Lin, Zer-Ming
;
Hsu, Hsing-Hui
In this work we report the observation and characterization of a hysteresis phenomenon in the transfer characteristics of n-channel polycrystalline silicon (poly-Si) thin-film transistors (TFTs). Such phenomenon is observed in devices with fully depleted channel and not treated with hydrogen-related anneal. The origin of the hysteresis is identified to be related to the electron trapping and detrapping processes associated with the deep-level traps in the grain boundaries of the poly-Si channel.
Poly-silicon nanowire field-effect transistor for ultrasensitive and label-free detection of pathogenic avian influenza DNA
(2009-06-15)
Lin, Chih-Heng
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Hung, Cheng-Hsiung
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Hsiao, Cheng-Yun
;
Lin, Horng-Chih
;
Ko, Fu-Hsiang
Enhanced surveillance of influenza requires rapid, robust. and inexpensive analytical techniques capable of providing a detailed analysis of influenza virus strains. Functionalized poly-crystalline silicon nanowire field-effect transistor (poly-SiNW FET) was demonstrated to achieve specific and Ultrasensitive (at fM level) detection of high pathogenic strain virus (H5 and H7) DNA of avian influenza (AI) which is an important infectious disease and has an immediate need for surveillance. The poly-SiNW FET was prepared by a simple and low-cost method that is compatible with Current commercial semiconductor process without expensive E-beam lithography tools for large-scale production. Specific electric changes were observed for AI virus DNA sensing when nanowire surface of poly-SiNW FET was modified with complementary captured DNA probe and target DNA (H5) at fM to pM range Could be distinguished. With its excellent electric properties and potential for mass commercial production, poly-SiNW FET car, be developed to become a portable biosensor for field use and point-of-care diagnoses. (C) 2009 Elsevier B.V. All rights reserved.
Selective real-time nitric oxide detection by functionalized zinc oxide
(2009-08-07)
Liu, Chien-Cheng
;
Li, Jan-Hao
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Chang, Cheng-Chung
;
Chao, Yu-Chiang
;
Meng, Hsin-Fei
Ferriprotoporphyrin IX chloride (haemin)-functionalized Al-doped zinc oxide (ZnO) is used for nitric oxide (NO) sensing at room temperature. The devices show high selectivity to NO against CO(2) and O(2). There is no such selectivity without haemin. Porous ZnO film made by a polystyrene sphere template is used to provide a high surface area. In comparison with non-porous ZnO film with low surface area, both the sensitivity and the response speed of the sensor made by porous ZnO are clearly improved. NO concentration down to 1 ppm can be detected. The response time is 20 s. The sensor is reversible after purging with pure nitrogen for about 100 s. Such a device is able to detect real-time variation of NO which is a vital physiological signalling molecule.
Ultrasensitive detection of dopamine using a polysilicon nanowire field-effect transistor
(2008)
Lin, Chih-Heng
;
Hsiao, Cheng-Yun
;
Hung, Cheng-Hsiung
;
Lo, Yen-Ren
;
Lee, Cheng-Che
An unprecedented high sensitive sensing of neurotransmitter dopamine at fM level was demonstrated using a poly-crystalline silicon nanowire field-effect transistor (poly-SiNW FET) fabricated by employing a simple and low-cost poly-Si sidewall spacer technique, which was compatible with current commercial semiconductor processes for large-scale standard manufacture.