Gao Xiaohui, Lu Yizhong, He Shuijian, Li Xiaokun, Chen Wei
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China; University of Chinese Academy of Sciences, Beijing 100039, China.
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Anal Chim Acta. 2015 Jun 16;879:118-25. doi: 10.1016/j.aca.2015.04.002. Epub 2015 Apr 3.
We report here a facile colorimetric sensor based on the N-acetyl-L-cysteine (NALC)-stabilized Ag nanoparticles (NALC-Ag NPs) for detection of Fe(3+) ions in aqueous solution. The Ag NPs with an average diameter of 6.55±1.0 nm are successfully synthesized through a simple method using sodium borohydride as reducing agent and N-acetyl-L-cysteine as protecting ligand. The synthesized silver nanoparticles show a strong surface plasmon resonance (SPR) around 400 nm and the SPR intensity decreases with the increasing of Fe(3+) concentration in aqueous solution. Based on the linear relationship between SPR intensity and concentration of Fe(3+) ions, the as-synthesized water-soluble silver nanoparticles can be used for the sensitive and selective detection of Fe(3+) ions in water with a linear range from 80 nM to 80 μM and a detection limit of 80 nM. On the basis of the experimental results, a new detection mechanism of oxidation-reduction reaction between Ag NPs and Fe(3+) ions is proposed, which is different from previously reported mechanisms. Moreover, the NALC-Ag NPs could be applied to the detection of Fe(3+) ions in real environmental water samples.
我们在此报告一种基于N-乙酰-L-半胱氨酸(NALC)稳定的银纳米颗粒(NALC-Ag NPs)的简易比色传感器,用于检测水溶液中的Fe(3+)离子。通过一种简单的方法,以硼氢化钠作为还原剂、N-乙酰-L-半胱氨酸作为保护配体,成功合成了平均直径为6.55±1.0 nm的Ag NPs。合成的银纳米颗粒在400 nm左右呈现出强烈的表面等离子体共振(SPR),并且SPR强度随着水溶液中Fe(3+)浓度的增加而降低。基于SPR强度与Fe(3+)离子浓度之间的线性关系,合成的水溶性银纳米颗粒可用于灵敏且选择性地检测水中的Fe(3+)离子,线性范围为80 nM至80 μM,检测限为80 nM。基于实验结果,提出了一种Ag NPs与Fe(3+)离子之间氧化还原反应的新检测机制,这与先前报道的机制不同。此外,NALC-Ag NPs可应用于实际环境水样中Fe(3+)离子的检测。