A highly sensitive non-aggregation colorimetric sensor for the determination of I− based on its catalytic effect on Fe3+ etching gold nanorods

• DOI: 10.1016/j.snb.2013.07.062
• Publication Date: 2013-07-29T05:57:03Z
• Authors: Jia-Ming Liu; Li Jiao; Ma-Lin Cui; Li-Ping Lin; Xin-Xing Wang; Zhi-Yong Zheng; Li-Hong Zhang; Shu-Lian Jiang
• Keywords: Nanorod; Absorbance

Abstract I − could accelerate the selective etching along longitudinal direction of gold nanorods (AuNRs) induced by Fe 3+ in HCl medium, which decreased the aspect ratio (length/width) of AuNRs, and thus the longitudinal surface plasmon resonance (LSPR) absorption peaks of AuNRs blue shifted (Δ λ = λ 0 − λ ), the corresponding absorbance decreased (Δ A = A 0 − A ), and the color of the solution obviously changed. Therefore, a non-aggregation AuNRs colorimetric sensor for the detection of I − was developed. The proposed colorimetric sensor is responsive, simple, selective and sensitive with the limit of quantization (LOQ) of 8.8 × 10 −8 M. The highly accurate sensor has been used to determine the content of I − in table salt samples with the results consistent with those obtained by inductively coupled plasma-mass spectroscopy (ICP-MS). Moreover, the morphological changes of AuNRs during the etching procedure were characterized by high resolution transmission electron microscopy (HRTEM) and the sensing mechanism for I − detection was also discussed.