Chemical redox-regulated mesoporous silica-coated gold nanorods for colorimetric probing of Hg2+ and S2-.
Chemical redox-regulated mesoporous silica-coated gold nanorods for colorimetric probing of Hg2+ and S2-.
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DOI：
10.1039/c0an00597e
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发表时间：
2011-01
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影响因子：
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通讯作者：
Guoqing Wang;Zhaopeng Chen;Wenhai Wang;B. Yan;Lingxin Chen
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文献类型：
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作者：
Guoqing Wang;Zhaopeng Chen;Wenhai Wang;B. Yan;Lingxin Chen
在过去的几年中，已经见证了金属纳米颗粒作为用于比色检测的理想报告物的广泛使用，其通常涉及分析物触发的所施加的纳米颗粒的聚集度的改变，并且因此胶体颜色的改变。然而，这些基于聚集的比色探针与许多缺点相关，包括纳米聚集体的稳定性差、需要复杂的功能化和输出信号的非线性。为了解决这些问题，我们在此采用介孔二氧化硅包覆的金纳米棒（MS AuNR）作为新型纳米复合材料，用于依赖于其化学氧化还原调节表面化学的非聚集基无标记比色传感。在我们的传感系统中，Hg（2+）离子被还原为Hg（0）离子沉积在MS AuNPs表面，导致MS AuNRs的颜色发生很大变化，而随后引入的S（2-）离子由于S（2-）离子对Hg（0）的萃取而导致相反的过程。汞（2+）和硫（2-）的比色传感的实验结果意味着相当高的灵敏度和特异性，表明我们的方法在未来的快速环境监测和生物分析的高潜力。
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.