Browsing by Author "Wei, Lan-Yi"

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Development of biosensor for protein tyrosine kinases
(2010-04-01)
Wei, Lan-Yi
;
Yuan, Chiun-Jye
;
生物科技學系
;
Department of Biological Science and Technology
Development of biosensor for protein tyrosine kinases
(2012-04-01)
Wei, Lan-Yi
;
Yuan, Chiun-Jye
;
生物科技學系
;
Department of Biological Science and Technology
Development of biosensor for protein tyrosine kinases
(2012-04-01)
Wei, Lan-Yi
;
Yuan, Chiun-Jye
;
生物科技學系
;
Department of Biological Science and Technology
Effect of anions on the oxidation and reduction of hydrogen peroxide on the gold nanoparticle-deposited carbon fiber paper electrode
(2015-10-20)
Lin, Chen-Han
;
Wei, Lan-Yi
;
Lee, Jhao-Hong
;
Lien, Chun-Lung
;
Lu, Chung-Hsiang
The nanostructured gold has been shown to catalyze the oxidation of hydrogen peroxide (H2O2), an important analyte for clinical diagnosis. However, little is known about the effect of anions on its catalytic activity. In this study the gold nanoparticles (AuNP) of average size of 30-80 nm were electrodeposited on the carbon fiber paper (CFP) electrode to explore the effect of anions, such as phosphate, sulfate, nitrate, acetate, chloride and hydroxide ions, on the AuNP-catalyzed H2O2-oxidation. In phosphate solution the AuNP-deposited CFP (AuNP/CFP) exhibited high catalytic activity to H2O2. However, the catalytic activity of AuNP was severed blocked in solutions containing chloride, sulfate, nitrate, and acetate ions. Although hydroxide was shown to facilitate the catalysis of AuNP, the oxidation of H2O2 was greatly interfered by the gold oxide formation in 0.05 M NaOH. A strong dipole moment between adsorbed anions, such sulfate, nitrate and acetate, and AuNP is suggested to block the access of H2O2 molecules to the surface of AuNPs. This postulation is demonstrated by the finding that the electrochemical active surface area of AuNP/CFP is 0.90 +/- 0.02 cm(2), 0.79 +/- 0.08 cm(2), 0.66 +/- 0.09 cm(2), 0.45 +/- 0.04 cm(2), 0.42 +/- 0.08 cm(2) and 0.15 +/- 0.08 cm(2), in 0.05 M hydroxide, phosphate, bicarbonate, nitrate, acetate and sulfate solutions, respectively. These results indicate that the microenvironment near the surface of nanostructured Au is important to determine the catalytic activity of Au to H2O2. (C) 2015 Elsevier Ltd. All rights reserved.
Reusable Amperometric Biosensor for Measuring Protein Tyrosine Kinase Activity
(2012-01-17)
Wang, Chung-Liang
;
Wei, Lan-Yi
;
Yuan, Chiun-Jye
;
Hwang, Kuo Chu
;
生物科技學系
This work presents a simple, low-cost and reusable label-free method for detecting protein tyrosine kinase activity using a tyrosinase-based amperometric biosensor (tyrosine kinase biosensor). This method is based on the observation that phosphorylation can block the tyrosinase-catalyzed oxidation of tyrosine or tyrosyl residue in peptides. Therefore, the activity of p60c-src protein tyrosine kinase (Src) on the developed tyrosine kinase biosensor could be quickly determined when its specific peptide substrate, p60c-src substrate I, was used. The tyrosine kinase biosensor was highly sensitive to the activity of Src with a linear dynamic range of 1.9-237.6 U/mL and the lowest detection limit of 0.23 U/mL. Interestingly, the tyrosine kinase activity can be measured using the developed tyrosine kinase biosensor repetitively without regeneration. The inhibitory effect of various kinase inhibitors on the Src activity could be determined on the tyrosine kinase biosensor. Src-specific inhibitors, PP2 and Src inhibitor I, effectively suppressed Src activity, whereas PD153035, an inhibitor of the epidermal growth factor receptor, was ineffective. Staurosporine, a universal kinase inhibitor, inhibited Src activity in an ATP concentration-dependent manner. These results suggests that the activities of tyrosine kinases and their behaviors toward various reagents can be effectively measured using the developed tyrosine kinase biosensor.