Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou, 350108, China.
J Am Chem Soc. 2013 Aug 21;135(33):12338-45. doi: 10.1021/ja405371g. Epub 2013 Aug 8.
The common drawbacks of current colorimetric sensors using gold nanoparticle aggregation is its relatively low sensitivity and narrow dynamic range, which restrict their application in real sample analysis when competing with other analytical techniques such as fluorescence and chemiluminescence. In this article, we demonstrate a novel strategy to construct colorimetric sensors based on gold nanoparticle aggregation. Unlike the conventional colorimetric sensors which cause the formation of large nanoparticle aggregates, in our strategy, dimers are selectively formed upon target binding, which results in significantly improved long-term stability and a more than 2 orders of magnitude wider dynamic range of detection than that of the conventional colorimetric sensors. In addition, a strategy to minimize the interparticle gap through the formation of a Y-shaped DNA duplex enables to increase the limit of detection by 10,000 times. The analytical figures of merit of the proposed sensor are comparable to those of the fluorescence-based sensors.
基于金纳米粒子聚集的比色传感器的常见缺点是其相对较低的灵敏度和较窄的动态范围，这限制了它们在与荧光和化学发光等其他分析技术竞争的实际样品分析中的应用。在本文中，我们展示了一种基于金纳米粒子聚集构建比色传感器的新策略。与传统的比色传感器会导致大的纳米粒子聚集形成不同，在我们的策略中，二聚体是在靶标结合时选择性形成的，这导致检测的长期稳定性显著提高，检测动态范围比传统的比色传感器宽两个数量级以上。此外，通过形成 Y 形 DNA 双链来最小化粒子间间隙的策略可将检测限提高 10000 倍。所提出的传感器的分析性能与基于荧光的传感器相当。
