Kim Kyungmin, Nam Yun-Sik, Lee Yeonhee, Lee Kang-Bong
Green City Technology Institute, Korea Institute of Science and Technology, Hwarang-ro 14gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea.
Department of Chemistry, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Republic of Korea.
J Anal Methods Chem. 2017;2017:3648564. doi: 10.1155/2017/3648564. Epub 2017 May 23.
A highly sensitive and simple colorimetric assay for the detection of Fe ions was developed using gold nanoparticles (AuNPs) conjugated with glycol chitosan (GC). The Fe ion coordinates with the oxygen atoms of GC in a hexadentate manner (O-Fe-O), decreasing the interparticle distance and inducing aggregation. Time-of-flight secondary ion mass spectrometry showed that the bound Fe was coordinated to the oxygen atoms of the ethylene glycol in GC, which resulted in a significant color change from light red to dark midnight blue due to aggregation. Using this GC-AuNP probe, the quantitative determination of Fe in biological, environmental, and pharmaceutical samples could be achieved by the naked eye and spectrophotometric methods. Sensitive response and pronounced color change of the GC-AuNPs in the presence of Fe were optimized at pH 6, 70°C, and 300 mM NaCl concentration. The absorption intensity ratio (/) linearly correlated to the Fe concentration in the linear range of 0-180 M. The limits of detection were 11.3, 29.2, and 46.0 nM for tap water, pond water, and iron supplement tablets, respectively. Owing to its facile and sensitive nature, this assay method for Fe ions can be applied to the analysis of drinking water and pharmaceutical samples.
使用与乙二醇壳聚糖（GC）共轭的金纳米颗粒（AuNP）开发了一种用于检测铁离子的高灵敏度且简单的比色测定法。铁离子以六齿方式（O-Fe-O）与GC的氧原子配位，减小颗粒间距离并诱导聚集。飞行时间二次离子质谱表明，结合的铁与GC中乙二醇的氧原子配位，由于聚集，导致颜色从浅红色显著变为深蓝色。使用这种GC-AuNP探针，可以通过肉眼和分光光度法对生物、环境和药物样品中的铁进行定量测定。在pH 6、70°C和300 mM NaCl浓度下优化了GC-AuNP在铁存在下的灵敏响应和明显颜色变化。吸收强度比（/）在0-180 M的线性范围内与铁浓度呈线性相关。自来水、池塘水和补铁片剂的检测限分别为11.3、29.2和46.0 nM。由于其简便性和灵敏性，这种铁离子测定方法可应用于饮用水和药物样品的分析。
