Browsing by Author "Wu, Chung-Shu"

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A highly sensitive and selective cyanide detection using a gold nanoparticle-based dual fluorescence-colorimetric sensor with a wide concentration range
(2016-05)
Cheng, Chieh
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Chen, Hsueh-Yang
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Wu, Chung-Shu
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Meen, Jagan Singh
;
Simon, Turibius
In this study, a simple analytical system is presented for the detection of cyanide with a wide concentration range, which is respectively based on the fluorescent and colorimetric properties of gold nanoparticles. This dual-functional system can work directly for aqueous medium and expand efficiently a wide detection range over three orders of magnitudes for cyanide determination. By using the fluorescence method, the lowest concentration for quantification of cyanide ions is 1.0 x 10(-7) M, and the sensitivity is good enough for the determination of cyanide in drinking water. To recognize higher concentration of cyanide for industrial sewage monitoring, the colorimetric behavior can be used as an alternating tool for field tests from naked eye. The system also provides an excellent selectivity toward cyanide over other common interfering anions and metal ions, thus enabling the ability to monitor cyanide contamination in environmental samples. Furthermore, several real water samples spiked with cyanide, including local tap water, drinking water, lake water, and sea water, were analyzed, and the experimental results demonstrated that this sensing system exhibited excellent recoveries for these practical water samples. Our attempt may provide a cost-effective, rapid and simple solution for the recognition and determination of different levels of cyanide contamination in aqueous samples. (C) 2015 Elsevier B.V. All rights reserved.
A rapid and portable sensor based on protein-modified gold nanoparticle probes and lateral flow assay for naked eye detection of mercury ion
(2012-09-01)
Chao, Cheng-Han
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Wu, Chung-Shu
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Huang, Chung-Chih
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Liang, Jie-Chian
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Wang, Hsiao-Ting
Contamination of the environment with heavy metal ions has been an important worldwide concern for decades. Among them, mercury ion (Hg2+) is one of the heavy metal ion maintained in the detection because of its toxicity. In this study, we have designed the gold nanoparticle (AuNP) probes of carboxylic modified protein and employed the lateral flow assay to detect the Hg2+ without complicated instrumentations and technical expertise. The captured AuNP probes on the test zone and control zone of the sensor produced the characteristic red bands, enabling visual discrimination of Hg2+ concentrations. The demand of Hg2+ analysis in environmental applications requires parallel analytical strategies; such a method with simplicity and rapidity has enormous potential for the application of Hg2+ monitoring in environment, water, and food samples. (C) 2012 Elsevier B.V. All rights reserved.
An enzymatic kinetics investigation into the significantly enhanced activity of functionalized gold nanoparticles
(2008)
Wu, Chung-Shu
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Wu, Chia-Tien
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Yang, Yuh-Shyong
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Ko, Fu-Hsiang
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材料科學與工程學系
Kinetic and thermodynamic studies reveal that the property of significantly enhanced catalytic activity with colloidal stability is attributed to an efficacious means of tuning enzyme-substrate association by varying with the rate constants in the presence of functionalized gold nanoparticles.
Catalytic Behaviors in Modulating Enzymatic Activity through Different-sized Gold Nanoparticles
(2010)
Wu, Chung-Shu
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Wu, Chia-Tien
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Chen, Chieh
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Huang, Chung-Chih
;
Yeh, Yu-Lin
We have demonstrated that gold nanoparticles (AuNPs) can effectively associate with enzyme through spontaneous adsorption to afford supramolecular complexes, resulting in a significant increase of its enzymatic activity. In this work, we embarked on a study of the interactions between the different-sized AuNPs and the substrate through quantifying the kinetic parameters (K(cat) and K(m)). The diversity of size allows us to probe the role of catalytic behaviors in modulating enzymatic activity.
Design of Artificial Hollow Moth-Eye Structures Using Anodic Nanocones for High-Performance Optics
(2010-12-28)
Wu, Chia-Tien
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Lin, Chun-Hung
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Cheng, Chieh
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Wu, Chung-Shu
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Ting, Huai-Chen
We demonstrated an innovative approach for the fabrication of self-organized, hollow-to-solid nanocone arrays, using a decoupling two-step anodization of an Al/Ta interlayer on a substrate. The porosity of the hollow nanostructures was tunable by the deposited thickness of Ta film. We also employed subwavelength nanocone arrays as Moth-eye structures for high-performance antireflection coatings. These oxide nanostructures greatly suppressed reflectance over a large range of wavelengths and angles of incidence and displayed a good mechanical stability. When a corresponding porosity was designed, these nanostructures could be applied to various substrates for an effective antireflection coating. In addition, we were able to customize antireflection coatings for various types of substrates or materials of interest based on the suitable coating of initial Ta thickness.
Environmentally Stable Flexible Metal-Insulator-Metal Capacitors Using Zirconium-Silicate and Hafnium-Silicate Thin Film Composite Materials as Gate Dielectrics
(2011-08-01)
Meena, Jagan Singh
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Chu, Min-Ching
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Wu, Chung-Shu
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Ravipati, Srikanth
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Ko, Fu-Hsiang
Fully flexible metal-insulator-metal (MIM) capacitors fabricated on 25 mu m thin polyimide (PI) substrates via the surface sol gel process using 10-nm-thick zirconium-silicate (ZrSi(x)O(y)) and hafnium-silicate (HfSi(m)O(n)) films as gate dielectrics. The surface morphology of the ZrSi(x)O(y) and HfSi(m)O(n) films were investigated using atomic force microscopy and scanning electron microscopy, which confirmed that continuous and crack-free surface growth had occurred on the PI. Both the films treated with oxygen (O(2)) plasma and annealing (ca. 250 degrees C) consisted of amorphous phase; confirmed by X-ray diffraction. We employed X-ray photoelectron spectroscopy (XPS) at high resolution to examine the chemical composition of the films subjected to various treatment conditions. The shift of the XPS peaks towards higher binding energy revealed the O(2) plasma-pretreatment followed by annealing was the most effective process to the surface oxidation at relatively low-temperature, for further passivate the grease traps and making dielectric films thermally stable. The ZrSi(x)O(y) and HfSi(m)O(n) films in sandwich-like MIM configuration on the PI substrates exhibited the low leakage current densities of 7.1 x 10(-9) and 8.4 x 10(-9) A/cm(2) at applied electric field of 10 MV/cm and maximum capacitance densities of 7.5 and 5.3 fF/mu m(2) at 1 MHz, respectively. In addition, the ZrSi(x)O(y) and HfSi(m)O(n), films in MIM capacitors showed the estimated dielectric constants of 8.2 and 6.0, respectively. Prior to use of flexible MIM capacitors in advanced flexible electronic devices; the reliability test was studied by applying day-dependent leakage current density measurements up to 30 days. These films of silicate-surfactant mesostructured materials have special interest to be used as gate dielectrics in future for flexible metal-oxide-semiconductor devices.
Facile synthesis of a biocompatible silver nanoparticle derived tripeptide supramolecular hydrogel for antibacterial wound dressings
(2016)
Simon, Turibius
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Wu, Chung-Shu
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Liang, Jie-Chuan
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Cheng, Chieh
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Ko, Fu-Hsiang
Realizing the widespread demand for biocompatible supramolecular hydrogel based wound dressings, we have developed an N-terminally 2(naphthalen-6-yl) acetic acid (Nap) protected Phe-Phe-Cys peptide (Nap-FFC) using a liquid phase method. This Nap-FFC peptide was used to design a supramolecular hydrogel via a self-assembling process. The Nap-FFC short peptides produced stable and transparent silver nanoparticle-based hydrogels (AgNPs@Nap-FFC) wherein the self-assembled Nap-FFC nanofibers acted as scaffolds for the mineralization of silver nanoparticles (AgNPs) and stabilizers of the synthesized AgNPs. The resultant AgNPs@Nap-FFC nanocomposites were characterized using ultraviolet-visible spectrophotometry (UV-vis spectroscopy), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX) studies. The AgNPs@Nap-FFC nanocomposites showed excellent monodispersity, long term stability, and functional flexibility in comparison to other AgNP based nanocomposites. Furthermore, AgNPs@Nap-FFC exhibited strong inhibition against both Gram-positive (methicillin-resistant Staphylococcus aureus) and Gram-negative (Acinetobacter baumannii) bacteria and, most importantly, they showed favorable biocompatibility towards human cervical carcinoma cells (HeLa cells). Hence, this study implies that AgNPs@Nap-FFC nanocomposites can easily be prepared in a cost-effective manner and can be used effectively for future antibacterial wound dressings.
Facile synthetic route to implement a fully bendable organic metal-insulator-semiconductor device on polyimide sheet
(2012-05-01)
Meena, Jagan Singh
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Chu, Min-Ching
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Wu, Chung-Shu
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Liang, Jie-Chian
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Chang, Yu-Cheng
Triblock copolymer surfactant, HO(CH2CH2O)(20)(CH2CH(CH3)O)(70)(CH2CH2O)(20)H (i.e. P123)-based nanocrystalline (nc)-TiO2 thin film had been synthesized on organic flexible polyimide (PI) sheet for their application in organic metal-insulator-semiconductor (MIS) device. The nc-TiO2 film over PI was successfully deposited for the first time by a systematic solution proceeds dip-coating method and by the assistance of triblock copolymer surfactant. The effect of annealing temperature (270 degrees C, 5 h) on the texture, morphology and time-induced hydrophilicity was studied by X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle system, respectively, to examine the chemical composition of the film and the contact angle. The surface morphology of the semiconducting layer of organic pentacene was also investigated by using AFM and XRD, and confirmed that continuous crystalline film growth had occurred on the nc-TiO2 surface over flexible PI sheet. The semiconductor-dielectric interface of pentacene and nc-TiO2 films was characterized by current-voltage and capacitance-voltage measurements. This interface measurement in cross-link MIS structured device yielded a low leakage current density of 8.7 x 10(-12) A cm(-2) at 0 to -5V, maximum capacitance of 102.3 pF at 1 MHz and estimated dielectric constant value of 28.8. Furthermore, assessment of quality study of nc-TiO2 film in real-life flexibility tests for different types of bending settings with high durability (c. a. 30 days) demonstrated a better comprehension of dielectric properties over flexible PI sheet. We expected them to have a keen interest in the scientific study, which could be an alternate opportunity to the excellent dielectric-semiconductor interface at economic and low temperature processing for large-area flexible field-effect transistors and sensors. (C) 2012 Elsevier B. V. All rights reserved.
Highly reliable Si(3)N(4)-HfO(2) stacked heterostructure to fully flexible poly-(3-hexylthiophene) thin-film transistor
(2011-08-01)
Meena, Jagan Singh
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Chu, Min-Ching
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Wu, Chung-Shu
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Chang, Feng-Chih
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Ko, Fu-Hsiang
A new and fully flexible Si(3)N(4)-HfO(2) stacked poly-(3-hexylthiophene) p-type thin film transistor (P3HT-TFT) was successfully fabricated on thin semi-transparent polyimide (PI) substrate. The success of the TFT manufacturing adopts: (a) very simple and cost-effective sol-gel spin-coating technique to obtain 10-nm high-k HfO(2) as dielectric layer over fully flexible PI substrate; (b) 50-nm silicon nitride (Si(3)N(4)) as the most efficient passivation layer on top of HfO(2) film; (c) bendable 30-nm P3HT channel film by spin-coating method. Current-electric field characteristics of HfO(2) layer in metal-insulator-metal (MIM) and TFT configurations, with or without Si(3)N(4) passivation layer, were carefully evaluated. The origin of unsatisfactory leakage current in MIM and TFT structures could be effectively suppressed by means of Si(3)N(4) film as the efficient passivation layer. The bottom-gate TFT demonstrated the on-to-off ratio 2 x 10(4) for drain current, -1.9 V threshold voltage and good saturation mobility (0.041 cm(2) V (1) s (1)). The proposed devices were examined in convex and concave types of various radii of curvature (R(C)) in order to explore the manufacturing feasibility and electrical reliability of the fully flexible TFT for practical applications. In addition, various folding times and environmental stability on aforementioned devices with respective to electrical performances were also evaluated. (C) 2011 Elsevier B.V. All rights reserved.
Highly reliable Si3N4-HfO2 stacked heterostructure to fully flexible poly-(3-hexylthiophene) thin-film transistor
(2011-08-01)
Meena, Jagan Singh
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Chu, Min-Ching
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Wu, Chung-Shu
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Chang, Feng-Chih
;
Ko, Fu-Hsiang
A new and fully flexible Si3N4-HfO2 stacked poly-(3-hexylthiophene) p-type thin film transistor (P3HT-TFT) was successfully fabricated on thin semi-transparent polyimide (PI) substrate. The success of the TFT manufacturing adopts: (a) very simple and cost-effective sol-gel spin-coating technique to obtain 10-nm high-k HfO2 as dielectric layer over fully flexible PI substrate; (b) 50-nm silicon nitride (Si3N4) as the most efficient passivation layer on top of HfO2 film; (c) bendable 30-nm P3HT channel film by spin-coating method. Current-electric field characteristics of HfO2 layer in metal-insulator-metal (MIM) and TFT configurations, with or without Si3N4 passivation layer, were carefully evaluated. The origin of unsatisfactory leakage current in MIM and TFT structures could be effectively suppressed by means of Si3N4 film as the efficient passivation layer. The bottom-gate TFT demonstrated the on-to-off ratio 2 x 10(4) for drain current, -1.9 V threshold voltage and good saturation mobility (0.041 cm(2) V (1) s (1)). The proposed devices were examined in convex and concave types of various radii of curvature (R-C) in order to explore the manufacturing feasibility and electrical reliability of the fully flexible TFT for practical applications. In addition, various folding times and environmental stability on aforementioned devices with respective to electrical performances were also evaluated. (C) 2011 Elsevier B.V. All rights reserved.
Knitting up 2,7-disubstituted carbazole based oligomers through supramolecular interactions for their application in organic thin film transistors
(2015-01-01)
Singh, Ranjodh
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Meena, Jagan Singh
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Wu, Chung-Shu
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Ko, Fu-Hsiang
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材料科學與工程學系
For the design and development of organic electronic devices, the main focus is particularly on the synthesis of new organic semiconductors and dielectric materials. Molecular engineering is another effective strategy, in this direction which has been explored successfully in this study through synthesis of a p-conjugated oligomer CbzTPAU2, with M-w = 2169. This bow shaped oligomer has its core unit made of 2,7-disubstituted carbazole which further has been connected to its end-terminal unit TPAU2 by 1,4-bis(decyloxy)-2,5-diethynylbenzene. The presence of a uracil moiety on end terminals of CbzTPAU2 has triggered the self-assembly of CbzTPAU2 molecules through knitting up of each of these single units through four Uracil-Uracil intermolecular hydrogen bonds (U center dot center dot center dot U) per CbzTPAU2 unit. An Atomic Force Microscope (AFM) study was employed to explore the directionality of hydrogen bonding. Further, the effect of solvent polarity on the stability of U center dot center dot center dot U bonding in CbzTPAU2 oligomers has also been reported here in this study. The potential of these self-assembled CbzTPAU2 oligomers when explored as charge transporting layers in OTFTs has shown p-type behaviour. The OTFT device bottom-gate, top-contact when fabricated on the heavily doped n-type Si wafer with SiO2 as a gate dielectric (200 nm) has shown a good on/off ratio 3.43 x 10(3) and with an average hole mobility of 0.167 cm(2) V-1 s(-1).
Label-free Detection of Prostate Specific Antigen Using a Silicon Nanobelt Field-effect Transistor
(2012-05-01)
Wu, Chi-Chang
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Pan, Tung-Ming
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Wu, Chung-Shu
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Yen, Li-Chen
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Chuang, Cheng-Keng
In this study, we proposed a silicon nanobelt field-effect transistor (FET) to detect prostate specific antigen (PSA). The nanobelt FET device displayed n-channel depletion characteristics. The immobilization of prostate specific antibody (anti-PSA) molecules was attached onto the nanobelt FET surface by using the aldehyde groups of glutaraldehyde linked to the amino groups of 3-aminopropyltriethoxysilane (APTES). The shift in the drain current vs time curves of a nanobelt FET biosensor revealed that the electrical signal had a logarithmic relationship with respect to the concentration of the PSA, and detection capability was estimated in the 5 pg/mL level. To enhance the sensitivity of a nanobelt FET biosensor, this biosensor was designed by inserting arginine molecules between glutaraldehyde and APTES. Therefore, the detection capability of the developed sensor was extended to 50 fg/mL. Also, the relationship between the current shift and the logarithm of PSA concentration was exhibited linearity in the range 50 fg/mL - 500 pg/mL. The excellent electrical results of this label-free PSA nanobelt FET biosensor suggested that such biosensor might be potentially useful tools for biological research and future prostate cancer screening.
Microwave-assisted Electroless Deposition of Silver Nanoparticles onto Multiwalled Carbon Nanotubes
(2012-05-01)
Wu, Chung-Shu
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Lee, Chung-Yang
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Chen, Jem-Kun
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Kuo, Shiao-Wei
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Fan, Shih-Kang
In this study, an efficient microwave-assisted self-organization of silver nanoparticles onto multiwalled carbon nanotubes (MWCNTs) is proposed. Silver nanoparticles anchor onto the surface of MWCNTs through self-assembly at the reaction condition of 160 degrees C. We mixed the MWCNTs with saturated silver nitrate/nitric acid solution, without adding a reductant or stabilizer, and then heated them in the closed microwave heating system. The oxidizing conditions create active sites on the surface of MWCNTs and the silver nanoparticles spontaneously align at these sites through electroless deposition. The growing nanoparticles have fcc structures and their density increases upon increasing the reaction time.
Miniaturized metal semiconductor metal photocurrent system for biomolecular sensing via chemiluminescence
(2009-09-01)
Lin, Chie-Chieh
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Ko, Fu-Hsiang
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Chen, Chun-Chi
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Yang, Yuh-Shyong
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Chang, Feng-Chi
A miniaturized metal semiconductor metal photodetector was developed as the core detector for chemiluminescence biosensor. The biosensor utilized the semiconductor manufacturing to fabricate the 83 interdigitated patterns of 250-nm metal line and 278-nm space in 100 mu m x 100 mu m active region. The established real-time detector was operated at 0.4 V to ensure the maximal signal to background ratio of 3600 under illumination intensity of 1.46 mW/cm(2). A chemiluminescence in the miniaturized chamber was successfully proposed to determine the model protein concentration in real-time analysis. Before the emission of light from the catalytic reaction of substrate, the model protein of streptavidin bound to horseradish peroxidase was successfully immobilized onto the sensor surface through the high-affinity conjugate with biotin. The detection limit of 4.76 nM for streptavidin analysis was obtained under the calibration curve of linear range over 5-100 nM with correlation coefficient of 0.9999.
New Synthesis Route of Hydrogel through A Bioinspired Supramolecular Approach: Gelation, Binding Interaction, and in Vitro Dressing
(2015-09-02)
Cheng, Chieh
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Tang, Meng-Che
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Wu, Chung-Shu
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Simon, Turibius
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Ko, Fu-Hsiang
Peptide-based supramolecular hydrogels have been comprehensively investigated in biomaterial applications because of their unique bioactivity, biofunctionality, and biocompatible features. However, the presence of organic building blocks in peptide-based hydrogels often results in low mechanical stability. To expand their practical use and range of applications, it is necessary to develop the tool kit available to prepare bioinspired, peptide-based supramolecular hydrogels with improved mechanical stability. In this paper, we present an innovative electrostatic and cross-linking approach in which naphthyl-Phe-Phe-Cys (NapFFC) oligopeptides are combined with gold nanoparticles (AuNPs) and calcium ions (Ca2+) to produce peptide-based supramolecular hydrogels. We further investigate the interactions among NapFFC, AuNPs and Ca" by microscopy. The morphology of the nanofibrous network constructions and the binding forces exhibited from the hydrogel demonstrated that the combination of two mechanisms successfully enhanced the mechanical stability through the formation of a densely entangled fibrous network of peptide multimers that is attributed to the AuNP linkage and Ca2+-induced agglomeration. UV vis spectrophotometry and fluorescence analysis were also used to demonstrate the enhanced stability of the hydrogel under various conditions such as thermal, solvent erosion, pH value and sonication. All results indicate that the presence of AuNPs and Ca2+ can strengthen the prepared hydrogel by more than doubling the diameter of NapFFC nanofibers, enabling the formation of stronger frameworks and slowing the release of components. Further experiments confirmed that HeLa cells can grow on the bioinspired NapFFC-AuNP hydrogel and exhibit high cell viability and that these cells were killed on contact with a hydrogel containing a drug. Our peptide-based supramolecular hydrogels prepared from the observed electrostatic and cross-linking mechanisn exhibited a significantly improved mechanical stability, making them well suited to use as a drug carrier in hydrogel dressings and as extracellular materials (ECMs) for tissue engineering.
Novel Chemical Route to Prepare a New Polymer Blend Gate Dielectric for Flexible Low-Voltage Organic Thin-Film Transistor
(2012-06-01)
Meena, Jagan Singh
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Chu, Min-Ching
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Chang, Yu-Cheng
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Wu, Chung-Shu
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Cheng, Chih-Chia
An organic-organic blend thin film has been synthesized through the solution deposition of a triblock copolymer (Pluronic P123, EO20-PO70-EO20) and polystyrene (PS), which is called P123-PS for the blend film whose precursor solution was obtained with organic additives. In addition to having excellent insulating properties, these materials have satisfied other stringent requirements for an optimal flexible device: low-temperature fabrication, nontoxic, surface free of pinhole defect, compatibility with organic semiconductors, and mechanical flexibility. Atomic force microscope measurements revealed that the optimized P123-PS blend film was uniform, crack-free, and highly resistant to moisture absorption on polyimide (PI) substrate. The film was well-adhered to the flexible Au/Cr/PI substrate for device application as a stable insulator, which was likely due to the strong molecular assembly that includes both hydrophilic and hydrophobic effects from the high molecular weights. The contact angle measurements for the P123-PS surface indicated that the system had a good hydrophobic surface with a total surface free energy of approximately 19.6 mJ m(-2). The dielectric properties of P123-PS were characterized in a cross-linked meta-insulator-metal structured device on the PI substrate by leakage current, capacitance, and dielectric constant measurements. The P123-PS film showed an average low leakage current density value of approximately 10(-10) A cm(-2) at 5-10 MV cm(-1) and large capacitance of 88.2 nF cm(-2) at 1 MHz, and the calculated dielectric constant was 2.7. In addition, we demonstrated an organic thin-film transistor (OTFT) device on a flexible PI substrate using the P123-PS as the gate dielectric layer and pentacene as the channel layer. The OTFT showed good saturation mobility (0.16 cm(2) V-1 s(-1)) and an on-to-off current ratio of 5 x 10(5). The OTFT should operate under bending conditions; therefore flexibility tests for two types of bending modes (tensile and compressive) were also performed successfully.
Polystyrene-block-poly(methylmethacrylate) composite material film as a gate dielectric for plastic thin-film transistor applications
(2014)
Meena, Jagan Singh
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Chu, Min-Ching
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Singh, Ranjodh
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Wu, Chung-Shu
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Chand, Umesh
We report a simple approach to fabricate an organic-inorganic hybrid gate insulator based n-type thin-film transistor (TFT) on a plastic polyimide (PI) sheet at room temperature using an appropriate composition of commercially available polymers and block copolymer surfactant. The composite material film namely; polystyrene-block-poly(methylmethacrylate) (PS-b-PMMA) is readily deposited as a gate dielectric with zinc oxide (ZnO) as a semiconductor layer. This new dielectric material film exhibits high surface energy, high air stability, very low leakage current density and better dielectric constant as compared to the conventional polymer dielectrics. This plastic ZnO-TFT combines the advantages of a high-mobility transparent inorganic semiconductor with an ultrathin high-capacitance and low-leakage PS-b-PMMA composite gate dielectric. Fourier transform infrared (FT-IR) spectrum analysis is used for the PS-b-PMMA film to confirm the presence of functional components in this composite material film. The contact angle measurements for three test liquids (e.g., distilled water, ethylene glycol and diiodomethane) reveal that the composite dielectric materials film is nearly hydrophobic and the calculated surface energy is 35.05 mJ m(-2). The resulting TFT exhibits excellent operating characteristics at V-DS=10 V with a drain-source current on/off modulation ratio (I-on/I-off) of 3.12 x 10(6) and a carrier mobility of 2.48 cm(2) V-1 s(-1). Moreover in the bending mode and in a normal environment, the device remained undistorted and shows better reliability and performance, while the thickness of PS-b-PMMA is about 28 nm. The results have suggested a new and easy approach for achieving transparent and functionally bendable optoelectronics devices.
Potential role of gold nanoparticles for improved analytical methods: an introduction to characterizations and applications
(2011-01-01)
Wu, Chung-Shu
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Liu, Fu-Ken
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Ko, Fu-Hsiang
;
材料科學與工程學系
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材料科學與工程學系奈米科技碩博班
Nanoparticle-based material is a revolutionary scientific and engineering venture that will invariably impact the existing analytical separation and preconcentration for a variety of analytes. Nanoparticles can be regarded as a hybrid between small molecule and bulk material. A material on the nanoscale produces considerable changes on various properties, making them size- and shape-dependent. Gold nanoparticles (Au NPs), one of the wide variety of core materials available, coupled with tunable surface properties in the form of inorganic or inorganic-organic hybrid have been reported as an excellent platform for a broad range of analytical methods. This review aims to introduce the basic principles, examples, and descriptions of methods for the characterization of Au NPs by using chromatography, electrophoresis, and self-assembly strategies for separation science. Some of the latest important applications of using Au NPs as stationary phases toward open-tubular capillary electrochromatography, gas chromatography, and liquid chromatography as well as roles of run buffer additive to enhance separation and preconcentration in the field of chromatographic, electrophoretic and in chip-based systems are reviewed. Additionally, we review Au NPs-assisted state-of-the-art techniques involving the use of micellar electrokinetic chromatography, an online diode array detector, solid-phase extraction, and mass spectrometry for the preconcentration of some chemical compounds and biomolecules.
Real-Time and Label-Free Detection of the Prostate-Specific Antigen in Human Serum by a Polycrystalline Silicon Nanowire Field-Effect Transistor Biosensor
(2013-08-20)
Huang, Yu-Wen
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Wu, Chung-Shu
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Chuang, Cheng-Keng
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Pang, See-Tong
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Pan, Tung-Ming
In this research, we used a polycrystalline silicon nanowire field-effect transistor (poly-Si NWFET) as a biosensor that employs the sidewall spacer technique instead of an expensive electron beam lithography method. When compared with commercial semiconductor processes, the sidewall spacer technique has the advantages of simplicity and low cost. hi this study, we employed a novel poly-Si NWFET device for real-time, label-free, and ultrahigh-sensitivity detection of prostate-specific antigen (PSA) in human serum. Since serum proteome is very complex containing high levels of salts and other interfering compounds, we hereby developed a standard operating procedure for real-sample pretreatment to keep a proper pH value and ionic strength of the desalted serum and also utilized Tween 20 to serve as the passivation agent by surface modification on the NWFET to reduce nonspecific binding for medical diagnostic applications. We first modified 3-aminopropyltriethoxysilane on the surface of a poly-Si nanowire device followed by glutaraldehyde functionalization, and the PSA antibodies were immobilized on the aldehyde terminal. While PSA was prepared in the buffers to maintain an appropriate pH value and ionic strength, the results indicated that the sensor could detect trace PSA at less than 5 fg/mL in a microfluidic channel. The novel poly-Si NWFET is developed as a diagnostic platform for monitoring prostate cancer and predicting the risk of early biochemical relapse.
Size-modulated catalytic activity of enzyme-nanoparticle conjugates: a combined kinetic and theoretical study
(2011)
Wu, Chung-Shu
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Lee, Cheng-Che
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Wu, Chia-Tien
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Yang, Yuh-Shyong
;
Ko, Fu-Hsiang
A series of experiments were performed to systematically analyze the effect of nanoparticle (NP) size on the catalytic behavior of enzyme-NP conjugates, and a shielding model based on diffusion-collision theory was developed to explain the correlation between the size effects and the kinetic responses.