Hou Xinyan, Chen Shu, Tang Jian, Xiong Yuan, Long Yunfei
Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China.
Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China.
Anal Chim Acta. 2014 May 12;825:57-62. doi: 10.1016/j.aca.2014.03.038. Epub 2014 Mar 29.
A colorimetric method for the recognition and sensing of iodide ions (I(-)) has been developed by utilizing the reactions between triangular silver nanoplates (TAg-NPs) and I(-) in the presence of sodium thiosulfate (Na2S2O3). Specifically, I(-) together with Na2S2O3 can induce protection of TAg-NPs owing to the formation of insoluble AgI, as confirmed by the high-resolution transmission electron microscopy (HRTEM). In the absence of Na2S2O3, the etching reactions on TAg-NPs were observed not only by I(-) but also other halides ions. The Na2S2O3 plays as a sensitizer in this system, which improved the selectivity and sensitivity. The desired colorimetric detection can be achieved by measuring the change of the absorption peak wavelength corresponding to localized surface plasmon resonance (LSPR) with UV-vis spectrophotometer or recognized by naked eye observation. The results show that the shift of the maximum absorption wavelength (Δλ) of the TAg-NPs/Na2S2O3/I(-) mixture was proportional to the concentration of I(-) in the range 1.0×10(-9)-1.0×10(-6) mol L(-1). Moreover, no other ions besides I(-) can induce an eye discernible color change as low as 1.0×10(-7) mol L(-1). Finally, this method was successfully applied for I(-) determination in kelp samples.
通过利用三角银纳米片（TAg-NPs）与碘离子（I(-)）在硫代硫酸钠（Na2S2O3）存在下的反应，开发了一种用于识别和传感碘离子（I(-)）的比色法。具体而言，I(-)与Na2S2O3一起可由于形成不溶性AgI而诱导对TAg-NPs的保护，高分辨率透射电子显微镜（HRTEM）证实了这一点。在没有Na2S2O3的情况下，不仅I(-)而且其他卤离子都观察到了对TAg-NPs的蚀刻反应。Na2S2O3在该系统中起敏化剂的作用，提高了选择性和灵敏度。所需的比色检测可以通过用紫外可见分光光度计测量对应于局域表面等离子体共振（LSPR）的吸收峰波长的变化来实现，或者通过肉眼观察来识别。结果表明，TAg-NPs/Na2S2O3/I(-)混合物的最大吸收波长（Δλ）的偏移在1.0×10(-9)-1.0×10(-6) mol L(-1)范围内与I(-)的浓度成正比。此外，除I(-)之外没有其他离子能在低至1.0×10(-7) mol L(-1)时引起肉眼可辨别的颜色变化。最后，该方法成功应用于海带样品中I(-)的测定。
