Browsing by Author "Chang, KS"

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Eliminating the interference of ascorbic acid and uric acid to the amperometric glucose biosensor by cation exchangers membrane and size exclusion membrane
(2005-12-01)
Yuan, CJ
;
Hsu, CL
;
Wang, SC
;
Chang, KS
;
生物科技學系
The characteristics of a multiuse planar amperometric biosensor modified with Nafion and/or polyion membrane were investigated. A new enzyme immobilization process was proposed, in which the polyvinyl alcohol bearing a styrylpyridinium (SbQ)/glucose oxidase composite was treated with glutaraldehyde vapor prior to the photo-crosslinking reaction. The resulting planar enzyme electrode remains active for at least 150 days. Compared with poly-L-lysine/poly (4-stryenesulfonate) polyion complex membrane the Nafion membrane showed marked effect to reduce the electrochemical response of the modified planar enzyme electrode to the biological interferents, such as ascorbic acid and uric acid. Furthermore, Nafion membrane can effective restricting the oxidized anionic interferent to adhear on its surface, thereby the fouling of the electrode was avoided.
Series quartz crystal sensor for remote bacteria population monitoring in raw milk via the Internet
(2006-02-15)
Chang, KS
;
Jang, HD
;
Lee, CF
;
Lee, YG
;
Yuan, CJ
A remote monitoring system based on a piezoelectric quartz crystal (SPQC) sensor was developed for the determination of the bacteria population in raw milk. The system employs the Windows XP server operating system, and its programs for data acquisition, display and transmission were developed using the LabVIEW 7.1 programming language. The circuit design consists of a circuit with a piezoelectric quartz crystal (SPQC) and a pair of electrodes. This system can provide dynamic data monitoring on a web-page via the Internet. Immersion of the electrodes in a cell culture with bacteria inoculums resulted in a change of frequency caused by the impedance change due to microbial metabolism and the adherence of bacteria on the surface of the electrodes. The calibration curve of detection times against density of bacteria showed a linear correlation coefficient (R-2 = 0.9165) over the range of 70-10(6) CFU ml(-1). The sensor could acquire sufficient data rapidly (within 4 h) and thus enabled real-time monitoring of bacteria growth via the Internet. This system has potential application in the detection of bacteria concentration of milk at dairy farms. (c) 2005 Elsevier B.V. All rights reserved.