Zirconia nanofibers made by the sol-gel method as a SERS substrate for trace detection of pesticides
| Autor: | Chih-ChienChen, 陳志堅 |
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| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Trace detection of pesticide residues is necessary to assure food safety, given the potential health risks the pesticide residues may pose to consumers, thus a simple, rapid and effective analytical method is required. Surface-enhanced Raman scattering (SERS) has been well developed for detecting target species. Herein, gold nanoparticles deposited onto a template zirconia nanofibers prepared by the spin-coated sol-gel method were used as SERS-active substrates. The morphologies of zirconia samples were easily controlled by adjusting the precursor concentrations. The SERS effects of samples were firstly evaluated by different laser wavelengths using rhodamine 6G (R6G) as the probe molecule. The sample Au/Z_0.3 exhibited the highest enhancement factor of 2.1 × 107. Furthermore, the optimized SERS-active substrates Au/Z_0.3 were competent to detect four types of pesticides, including phosmet, carbaryl, permethrin and cypermethrin. The limits of detection were 10-6 M for cypermethrin, 10-7 M for carbaryl and permethrin, and 10-8 M for phosmet. In the Raman analysis of mixed pesticides, the substrates showed high selectivity to organophosphates. Finally, the characteristic peaks of each pesticide could be still identified in the simulation of detecting pesticides on fruits. The results show that the sample Au/Z_0.3 is a promising tool for trace detection of pesticides on fruits. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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