| Summary: | 碩士 === 高雄醫學大學 === 醫學檢驗生物技術學系碩士班 === 106 === Analytical techniques for trace element analysis have been well established based on the combination of various techniques and instruments, such as atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). However, the practicability of these analytical methods was limited by various requirements, such as sample volume, apparatus required and sample pretreatment processes. Recently, due to the unique optical characteristics of nanomaterials, various nanomaterial-based analytical methods have been reported. The aim of the study was to develop a simple nanomaterial-based analytical method for the quantification of trivalent chromium (Cr3+).
An eco-friendly and highly selective gold nanoparticles (AuNPs) has been prepared and functionalized by glutathione (GSH). The presence of Cr3+ induced aggregation of GSH@AuNPs, yielding a color change from red to blue by the naked eye and monitored using UV–Vis spectroscopy. To optimize the analytical characteristics of the proposed method, the concentration and reaction time of GSH, the working pH, reaction times, and the selectivity were evaluated. Under the optimized conditions, the concentration of GSH was 1.0 mM, the reaction time was 10 minutes, and the reaction pH was 3.0. According to the experimental results, the analytical performance was as the following: the absorbance ratio (A700/522) is linearly related to the Cr3+ concentration in the range of 0.3-1.5
mg L-1 (R2 = 0.9971), and the limit of detection (LOD) was 0.03 mg L-1 (n = 7), RSD was 3.9 %, and the average recovery values was 105.6%; the GSH-AuNPs bound to Cr3+ with excellent selectivity relative to other metal ions (Cr6+, Cu2 +, Cd2 +, Mn2 +, Mg2 +, Ni2 +, Co2 +, Zn2 +, Fe2 +, Pb2 +, Hg2 +and As5+), leading to a prominent color change. After optimization the preparation conditions, the GSH@AuNPs was used to detect the amounts of Cr3+ species in tap water and nutritional supplementary milk samples.
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