He Haihan, Hao Rui
Department of Chemistry, Southern University of Science and Technology, 518055 Shenzhen, China.
Research Center for Chemical Biology and Omics Analysis, Southern University of Science and Technology, 518055 Shenzhen, China.
Nano Lett. 2024 Sep 4;24(35):11051-11058. doi: 10.1021/acs.nanolett.4c03199. Epub 2024 Aug 28.
A major challenge for ultrasensitive analysis is the high-efficiency determination of different target single molecules in parallel with high accuracy. Herein, we developed a quantitative fluoro-electrochemical imaging approach for direct multiplexed single-molecule counting with a SiC-nanofilm-modified indium tin oxide transparent electrode. The nanofilm could control local pH through proton-coupled electron transfer in a lower potential range and further induce direct electrochemical oxidation of the dye molecules with a higher applied potential. The fluoro-electrochemical responses of immobilized single molecules with different pH values and redox behaviors could thus be distinguished within the same fluorescence channels. This method yields nonamplified direct counting of single molecules, as indicated by excellent linear responses in the picomolar range. The successful distinction of seven different randomly mixed dyes underscores the versatility and efficacy of the proposed method in the highly accurate determination of single dye molecules, paving the way for highly parallel single-molecule detection for diverse applications.
超灵敏分析面临的一个主要挑战是高效、准确地并行测定不同的目标单分子。在此，我们开发了一种定量荧光电化学成像方法，以碳化硅纳米膜修饰的氧化铟锡透明电极进行直接多重单分子计数。该纳米膜可通过在较低电位范围内的质子耦合电子转移来控制局部pH值，并在较高施加电位下进一步诱导染料分子的直接电化学氧化。因此，在相同的荧光通道内可以区分具有不同pH值和氧化还原行为的固定化单分子的荧光电化学响应。如皮摩尔范围内出色的线性响应所示，该方法可实现单分子的非放大直接计数。成功区分七种不同的随机混合染料，突出了所提出方法在高精度测定单染料分子方面的通用性和有效性，为多种应用的高度并行单分子检测铺平了道路。
