Browsing by Author "Weng, Chang-Ching"

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An antifouling peptide-based biosensor for determination of Streptococcus pneumonia markers in human serum
(2020-03-01)
Chang, Po-Han
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Weng, Chang-Ching
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Li, Bor-Ran
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Li, Yaw-Kuen
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交大名義發表
We report a peptide-based sensor that involves a multivalent interaction with L-ascorbate 6-phosphate lactonase (UlaG), a protein marker of Streptococcus pneumonia. By integrating the antifouling feature of the sensor, we significantly improved the signal-to-noise ratio of UlaG detection. The antifouling surface was fabricated via electrodeposition using an equivalent mixture of 4-amino-N,N,N-trimethylanilinium and 4-aminobenzenesulfonate. This antifouling layer not only effectively reduces the non-specific adsorption on the biosensor but also decreases the charge transfer resistance (R-et) of the screen-printed carbon electrode. The aniline-modified 57 peptide, an UlaG-binding peptide, was pre-synthesized and further electrochemically modified to bind onto the antifouling layer. Bio-electrochemical analysis confirms that the antifouling 57-peptide sensor binds strongly to the UlaG with a dissociation constant (K-d) = 0.5 nM. This strong interaction can be attributed to a multivalent interaction between the biosensor and the heximeric form of UlaG. To demonstrate the potential for clinical application, further detection of Streptococcus pneumonia from 50 to 5 x 10(4) CFU/mL were successfully performed in 25% human serum.
Development of a novel engineered antibody targeting Neisseria species
(2017-03)
Liu, Chih-Yueh
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Weng, Chang-Ching
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Lin, Chih-Hsiang
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Yang, Chiou-Ying
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Mong, Kwok-Kong Tony
A Neissaria bacterial pilus sugar, bacillosamine, was synthesized and, for the first time, used as a probe to screen a single-chain variable fragment (scFv). Four Neisseria, Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria sicca and Neisseria subflava, and two negative controls, Streptococcus pneumoniae and Escherichia coli, were tested through ELISA, immunostaining and gold nanoparticle immunological assay. All results indicated that the selected scFv is feasible for the specific detection of Neisseria species via the recognition of bacillosamine. The recombinant scFv could detect Neisseria strains at 10(6) CFU/ml.
Snake Tracks in Polymer Land: Wavy Polymer Structures via Selective Solvent Vapor Annealing
(2020-08-25)
Chiu, Yu-Jing
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Weng, Chang-Ching
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Tseng, Hsiao-Fan
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Hsu, Hsun-Hao
;
Chen, Jiun-Tai
Wavy patterns are interesting geometric patterns and commonly seen in nature, such as serpentine streams or snake tracks in the sand. Although many efforts have been devoted to fabricating artificial wavy structures, it remains a great challenge to obtain wavy structures with controllable curvatures and desired functional properties. Here, we present an unprecedented approach to generate wavy polymer structures by annealing electrospun core-shell fibers on polymer films. Polystyrene (PS)/poly(methyl methacrylate) (PMMA) core-shell fibers, produced via the viscosity-induced phase separation in the electrospinning process, are annealed on PMMA films using vapors of acetic acid, a selective solvent for PMMA but not for PS. After the swollen PMMA chains of the PMMA shells are shed, the revealed PS cores start to buckle, driven by the elastic force from the strain release, forming the wavy structures. The degrees of the buckling, measured by the curvatures and the amplitudes of the wavy structures, are controlled by the annealing times. Furthermore, fluorescent properties are selectively introduced to the wavy structures using pyrene solutions or pyrene-containing vapors, demonstrating the potential application as fluorescent wavy materials.
Sunny-Side-Up Egg-Shaped Structures: Surface Modification To Form Anisotropic Polymer Particles Driven by the Plateau-Rayleigh Instability as Fluorescence Manipulation Platforms
(2019-02-26)
Chiu, Yu-Jing
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Liu, Chih-Ting
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Weng, Chang-Ching
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Chiu, Tang-Yao
;
Li, Jia-Wei
The Plateau-Rayleigh instability is a phenomenon driven by the reduction of the surface energies, in which a liquid cylinder transforms to a series of droplets with distinct spacing. This instability phenomenon is also applied broadly for the transformation of cylindrical materials to spherical particles in homogeneous environments. The demonstration of the instability in heterogeneous environments, however, has been less studied. Here, we study the Plateau-Rayleigh instability of electrospun polystyrene (PS)/poly(methyl methacrylate) (PMMA) core-shell fibers annealed on n-octadecyl-trichlorosilane (ODTS)-modified glass substrates with toluene vapors. After the annealing procedures, the PS/PMMA core-shell fibers transform to anisotropic sunny-side-up egg-shaped polymer structures, driven by the reduction of the total surface and interfacial energies. Quantitative analyses are performed on the sizes of the structures. Fluorescent fibers are also prepared by electrospinning and annealed on the ODTS-modified substrates, demonstrating the potential application as fluorescence manipulation platforms.