Aggregation induced photoacoustic detection of mercury (Ⅱ) ions using quaternary ammonium group-capped gold nanorods

Yan Huang; Fan Li; Gongcheng Ma; Wuwei Yang; Xiaofen Zhang; Jing Lin; Yongxiang Luo; Peng Huang

doi:10.1016/j.talanta.2018.05.002

Aggregation induced photoacoustic detection of mercury (Ⅱ) ions using quaternary ammonium group-capped gold nanorods

Talanta. 2018 Sep 1:187:65-72. doi: 10.1016/j.talanta.2018.05.002. Epub 2018 May 5.

Authors

Yan Huang¹, Fan Li¹, Gongcheng Ma¹, Wuwei Yang¹, Xiaofen Zhang², Jing Lin¹, Yongxiang Luo³, Peng Huang⁴

Affiliations

¹ Guangdong Key L aboratory for Biomedical Measurements and Ultrasound Imaging, Laboratory of Evolutionary Theranostics, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China.
² School of Public Health, Xiamen University, Xiang'an South Rd, Xiamen 361102, China.
³ Guangdong Key L aboratory for Biomedical Measurements and Ultrasound Imaging, Laboratory of Evolutionary Theranostics, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China. Electronic address: luoyongxiang@szu.edu.cn.
⁴ Guangdong Key L aboratory for Biomedical Measurements and Ultrasound Imaging, Laboratory of Evolutionary Theranostics, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China. Electronic address: peng.huang@szu.edu.cn.

PMID: 29853067
DOI: 10.1016/j.talanta.2018.05.002

Abstract

Photoacoustic imaging is an emerging detection tool of metal ions. Mercury is a typical heavy metal pollutant that can cause severe water and soil pollution. Therefore, it is particularly meaningful to develop a photoacoustic probe with excellent selectivity and sensitivity for the detection of mercury ions. In this study, gold nanorods modified with (11-mercapto-undecyl)-trimethylammonium (MTA) molecules containing sulfydryl groups were designed and synthesized for the photoacoustic detection of mercury ions (Hg²⁺). In the present of Hg²⁺, MTA molecules would be displaced quickly from the surface of gold nanorods due to the high affinity of Hg²⁺ toward sulfydryl group. Then gold nanorods were aggregated due to the loss of ligand protection on their surface, resulting in the enhancement of photoacoustic signals. In addition, this work showed a good linear relationship between the change of photoacoustic signal at 780 nm and the concentrations of Hg²⁺ (0-10 µM). More importantly, the devised photoacoustic detection system performs good stability and anti-interference compared to the traditional colorimetric detection system, making it possible to apply to the actual Hg²⁺-contaminated water samples.

Keywords: Aggregation; Gold nanorods; Mercury ions; Photoacoustic detection; Sulfydryl group.