| Summary: | 碩士 === 國立彰化師範大學 === 化學系 === 105 === In this work, different shapes of gold nanostructures (Au NSs: spherical, star, irregular) and different sizes of silver nanoparticles (Ag NPs: 13-84 nm) combining silver microstructure deposited on screen printed carbon electrode(AgMFs-SPCE) were used to explore the enhancement efficiency of surface enhanced Raman scattering (SERS) by using 4-mercaptobenzoic acid (4-MBA) as a Raman report. The Raman signal intensity was enhanced about 3.6-7.0 folds, depending on different shape of Au NSs. In addition, the Raman intensity by using Ag NPs/AgMFs-SPCE was 1.9 folds higher than that by using Au NPs/AgMFs-SPCE. Furthermore, the bigger size of Ag NPs was used, the better enhancement of Raman signal was found. Comparing to the absence AgMFs, the Raman signal intensity in the presence of AgMFs was increased about 1.2-3.9 folds. In addition, the Raman signal stabilities of the Ag NPs/AgMFs-SPCE at high temperature and long-term used were further explored. The Raman signal intensity were decreased 73% and 59% at 100oC condition and 10 days used, respectively. Comparing to Ag NPs/SPCE or AgMFs-SPCE, the proposed SERS substrate exhibits high temperature tolerance and long-term used properties. Finally, the proposed AgMFs-SPCE SERS substrate combining catalytic activity of Ag NPs was used to determine the concentration of Hg2+ ions. The formation of Ag-Au NPs deposited on the AgMFs-SPCE substrate leads to a significant decrease in Raman signal of 4-MBA, which is dependent on the Hg2+ ions concentration. A linear relationship was found between the Raman signal intensity and Hg2+ ions concentration over the range 0.1 nM-100 μM, and the LOQ was 0.1 nM. Using this technique suggests that Ag NPs/AgMFs-SPCE SERS substrate will be well suited for monitoring Hg2+ ions in the environment water sample in the future, because the highest concentration permitted in drinking water by the US EPA is 10 nM.
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