| Summary: | 碩士 === 國立陽明大學 === 生醫光電研究所 === 107 === Surface enhanced Raman spectroscopy (SERS) has been used for the detection of mercury ions (Hg2+) in spiked cosmetic (skin whitening) samples by using Fe3O4@Ag-DMcT nanoparticles (NPs). Silver (Ag) coated iron oxide (Fe3O4) NPs (12±4 nm) are the magneto-plasmonic SERS enhancers, and the 2,5-Dimercapto-1,3,4-thiadiazole (DMcT) 1360 cm-1 band as the Hg2+ reporter. The elemental composition was confirmed by energy dispersive analysis of X-ray (EDAX) mapping, and the functionalization with DMcT was confirmed by UV-Vis spectroscopy. We have optimized 2 mg/ml of Fe3O4@Ag:DMcT with 10-4 M of DMcT to be the best SERS enhancer in our study that we did in the solution phase inside a sealed capillary tube placed on a magnet. A calibration curve of the variation of the 1360 cm-1 band as a function of Hg2+ concentration was first determined. We did the recovery study in the spiked samples (commercial skin whitening product) and obtained the accuracy of intensity value of 81.1±35.3%, and 91.7±14.6% in low (0.00000001 M), and high (0.0001 M) spike concentrations, respectively, estimated from the calibration curve. We estimate a limit of detection (LoD) for Hg2+ in real cosmetic sample as 0.00000001 M (2 ppb).
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