Department of Physical and Inorganic Chemistry and EMaS , Universitat Rovira I Virgili , Carrer de Marcel.lí Domingo s/n , 43007 Tarragona , Spain.
ICREA , Passeig Lluís Companys 23 , 08010 Barcelona , Spain.
Anal Chem. 2019 Sep 17;91(18):11778-11784. doi: 10.1021/acs.analchem.9b02385. Epub 2019 Aug 26.
The combination of molecular sensors and plasmonic materials is emerging as one of the most promising approaches for ultrasensitive SERS-based detection of metal ions in complex fluids. However, only a very small fraction of the large pool of potential chemosensors described in classical analytical chemistry has been successfully implemented into viable SERS platforms for metal ion determination. This is due to the molecular restrictions that require the chemosensor to adhere onto the plasmonic surface while retaining the capability to undergo large structural alterations upon metal ion binding. In this work, we demonstrate that the structural and functional plasticity of DNA for interacting with small aromatic molecules can be exploited to this end. DNA coating of silver nanoparticles modulates the interaction of the commercially available alizarin red S (ARS) chemosensor with the nanomaterial, translating its recognition capabilities from bulk solution onto the plasmonic surface, while simultaneously directing the particle assembling into highly efficient SERS clusters. The sensing approach was successfully applied to the multiplex, quantitative determination of Al(III) and Fe(III) in tap water in the subppb level.
分子传感器与等离子体材料的结合，正在成为最有前途的方法之一，可用于在复杂流体中进行超灵敏基于 SERS 的金属离子检测。然而，在经典分析化学中描述的大量潜在化学传感器中，只有一小部分被成功地应用于可行的 SERS 平台，用于金属离子的测定。这是由于分子限制，需要化学传感器附着在等离子体表面上，同时保留在金属离子结合时发生大的结构改变的能力。在这项工作中，我们证明了 DNA 与小分子相互作用的结构和功能的可变性可以被利用到这一点。银纳米粒子的 DNA 涂层调节了市售茜素红 S（ARS）化学传感器与纳米材料的相互作用，将其识别能力从体相溶液转移到等离子体表面，同时将粒子组装成高效的 SERS 簇。该传感方法成功地应用于自来水中的 Al(III)和 Fe(III)的多重、定量测定，检测下限达到亚 ppb 级。
