Browsing by Author "Lien, Chun-Lung"

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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.
The Development of CMOS Amperometric Sensing Chip with a Novel 3-Dimensional TiN Nano-Electrode Array
(2019-03-01)
Lien, Chun-Lung
;
Yuan, Chiun-Jye
;
交大名義發表
;
生物科技學系
;
分子醫學與生物工程研究所
An electrochemical sensing chip with an 8 x 8 array of titanium nitride three-dimensional nano-electrodes (TiN 3D-NEA) was designed and fabricated via a standard integrated complementary metal oxide semiconductor process. Each nano-electrode in 3D-NEA exhibited a pole-like structure with a radius of 100 nm and a height of 35 nm. The numeric simulation showed that the nano-electrode with a radius of around 100 nm exhibited a more uniformly distributed electric field and a much higher electric field magnitude compared to that of the microelectrode. Cyclic voltammetry study with Ru(NH3)(6)(3+) also revealed that the TiN 3D-NEA exhibited a much higher current density than that obtained from the microelectrode by two orders of magnitude. Further studies showed that the electrocatalytical reduction of hydrogen peroxide (H2O2) could occur on a TiN 3D-NEA-based sensing chip with a high sensitivity of 667.2 mAmM(-1)cm(-2). The linear detection range for H2O2 was between 0.1 M and 5 mM with a lowest detection limit of 0.1 M. These results indicated that the fabricated TiN 3D-NEA exhibited high catalytic activity and sensitivity to H2O2 and could be a promising sensor for H2O2 measurement.