Physics of Complex Fluids Group and MESA+ Institute, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Laoshan District, Qingdao, 266101, P. R. China.
Anal Chem. 2021 Sep 28;93(38):12966-12972. doi: 10.1021/acs.analchem.1c02581. Epub 2021 Sep 14.
We demonstrate how algorithm-improved confocal Raman microscopy (ai-CRM), in combination with chemical enhancement by two-dimensional substrates, can be used as an ultrasensitive detection method for rhodamine (R6G) molecules adsorbed from aqueous solutions. After developing a protocol for laser-induced reduction of graphene oxide, followed by noninvasive Raman imaging, a limit of detection (LOD) of 5 × 10 M R6G was achieved using ai-CRM. An equivalent subnanomolar LOD was also achieved on another graphene oxide analogue -UV/ozone-oxidized graphene. These record-breaking detection capabilities also enabled us to study the adsorption kinetics and image the spatial distribution of the adsorbed R6G. These findings indicate a strong potential for algorithm-improved graphene-enhanced Raman spectroscopy as a facile method for detecting, imaging, and quantifying trace amounts of adsorbing molecules on a variety of 2D substrates.
我们展示了如何将算法改进的共焦拉曼显微镜（ai-CRM）与二维基底的化学增强相结合，用作从水溶液中吸附的罗丹明（R6G）分子的超灵敏检测方法。在开发了用于激光诱导还原氧化石墨烯的方案之后，通过非侵入性的拉曼成像，使用 ai-CRM 实现了 5×10^-7 M R6G 的检测限（LOD）。在另一种氧化石墨烯类似物-UV/臭氧氧化石墨烯上，也实现了等效的亚纳摩尔 LOD。这些破纪录的检测能力还使我们能够研究吸附的 R6G 的吸附动力学并对其空间分布进行成像。这些发现表明，算法改进的石墨烯增强拉曼光谱具有很大的潜力，可作为在各种二维基底上检测、成像和定量痕量吸附分子的简便方法。
