Chemical redox-regulated mesoporous silica-coated gold nanorods for colorimetric probing of Hg2+ and S2-.
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.
Wang
Guoqing
G
Key Laboratory of Coastal Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 17 Chunhui Road, Yantai 264003, China.
Chen
Zhaopeng
Z
Wang
Wenhai
W
Yan
Bing
B
Chen
Lingxin
L
D003124:Colorimetry / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013455:Sulfur / Q000032:analysis*
D013455:Sulfur; D006046:Gold; D012822:Silicon Dioxide; D008628:Mercury