Disposable sensing tube combined with single-fiber SERS sensor for Determination of Creatinine in Urine
| Autor: | Ming-Chao Chien, 錢明照 |
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| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 In this study, several single-fiber SERS sensors were fabricated and compared with conventional single-fiber SERS sensors to examine the performance for the new sensors. Single-fiber SERS sensors prepared in this work were composed with a tip modified optical fiber, a light collector and a silver nanoparticles (AgNPs) decorated porous membrane. The tip of optical fiber with a diameter ranged from 50 µm to 550 µm was etched by HF and a cone-shape tip could be successfully formed. The formed sensing tip could be further decoration of AgNPs via silver mirror reaction. For the preparation of light collector, silver mirror reaction to form a continuous silver thin film on glass tubes with different inner diameter was used. Commercial porous membrane was prepared by decorating AgNPs in the membranes of Nylon and Polyethersulfone (PES) with different pore sizes. By fixing AgNPs decorated membrane on the end of light collector, the optical fiber can be placed into this light collect. After adjusting the tip position to the surface of membrane, the new type of disposable single-fiber SERS sensor can be constructed. After probed with para-nitrothiophenol (pNTP), the detected SERS intensity was increased at least three times. The contributions from light collector, membrane or the fiber itself to the detected SERS signal were systematically examined. Results showed that major SERS signal was from the AgNPs decorated membrane. Light collector also improves the sensitivity in detection as the SERS intensity increases about 1.5 fold. The fabricated single-fiber SERS sensor was also applied to detect creatinine in aqueous solution to examine any degradation of the response time. To simplify the detection, optical fiber without decoration of AgNPs was used. Based on the detection time profile for creatinine, the membrane did not degrade the response time seriously as equilibrium could be reached within 15 min. Based on the detected signal, sensors prepared in this work show a detection limit close to 20 µM with a linear range up to 500 µM. These results indicate that a disposable single-fiber SERS sensor was successfully prepared in this work.. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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