Department of Applied Chemistry, School of Engineering , The University of Tokyo , 7-3-1, Hongo, Bunkyo, Tokyo 113-8656 , Japan.
Anal Chem. 2019 Aug 6;91(15):9741-9746. doi: 10.1021/acs.analchem.9b01334. Epub 2019 Jul 23.
Integrating analytical systems in 10-10 nm spaces provides ultrasensitive analytical devices at the single cell and the single molecule levels due to the ultrasmall space, and fundamental technologies for nanofluidics are developed. A simple and ultrasensitive detection method is one of the essential technologies for nanofluidics; however, it is still challenging due to the ultrasmall volume at the attoliter to femtoliter scale. In this study, we report a new photothermal detection method of nonfluorescent molecules for a 10 nm space, photothermal optical diffraction (POD), which utilizes light absorption and heat generation by an analyte and optical diffraction by a nanochannel after heat diffusion. Concentration determination of nonfluorescent molecules in a 400 nm channel was successfully demonstrated, and a limit of detection (LOD) of 5.0 μM was achieved, corresponding to 500 molecules (0.84 zmol) in a detection volume of 230 aL. Also, detection in a 200 nm channel was successfully demonstrated without degradation of the LOD. Our method can be widely used for chemical and biological analyses in 10-10 nm nanofluidics.
在 10-10nm 空间中集成分析系统，由于超小的空间，提供了单细胞和单分子水平的超高灵敏度分析设备，并开发了用于纳流控的基础技术。简单和超高灵敏度的检测方法是纳流控的关键技术之一；然而，由于在阿托升至飞升的极微小体积，仍然具有挑战性。在这项研究中，我们报告了一种用于 10nm 空间的非荧光分子的新光热检测方法，即光热光学衍射（POD），它利用分析物的光吸收和热产生以及纳米通道的热扩散后的光学衍射。成功地演示了在 400nm 通道中非荧光分子的浓度测定，检测限（LOD）达到 5.0μM，对应于检测体积为 230aL 中的 500 个分子（0.84zmol）。此外，在 200nm 通道中也成功地进行了检测，而没有降低 LOD。我们的方法可以广泛应用于 10-10nm 纳流控中的化学和生物学分析。
