中国科学院海岸带环境过程与生态修复重点实验室知识库

[Wang, GQ; Chen, ZP; Wang, WH; Chen, LX] Chinese Acad Sci, Yantai Inst Coastal Zone Res, Key Lab Coastal Environm Proc, Yantai 264003, Peoples R China; [Yan, B] Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China; [Yan, B] St Jude Childrens Hosp, Memphis, TN 38105 USA

The past a few years have witnessed the wide use of metallic nanoparticles as ideal reporters for colorimetric detection, which generally involves an analyte-triggered alteration of aggregation degree of applied nanoparticles, and thus the change of colloidal color. However, these aggregation-based colorimetric probe are associated with a number of drawbacks, including poor stability of nanoaggregates, requirement of complicated functionalization and non-linearity of output signals. To address these problems, we herein employ mesoporous silica-coated gold nanorods ( MS AuNRs) as novel nanocomposites for non-aggregation-based label-free colorimetric sensing relying on their chemical redox-modulated surface chemistry. In our sensing system, Hg(2+) ions are reduced to Hg(0) depositing on the surface of MS AuNPs and result in a great color change of MS AuNRs, while the subsequent introduction of S(2-) leads to a reverse process owing to the extraction of Hg(0) by S(2-). The experimental results for colorimetric sensing of Hg(2+) and S(2-) imply considerable sensitivity and specificity, suggesting the high potential of our approach for rapid environmental monitoring and bioanalysis in the future.