Deng Mingquan, Dou Xiujie, Wang Xiaoyu, Yin Yin, Guan Xun, Ma Libo, Ma Xing, Wang Jiawei
School of Integrated Circuits, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570228, China.
Front Optoelectron. 2025 Jul 28;18(1):15. doi: 10.1007/s12200-025-00159-1.
Understanding the sorption dynamics between water molecules and various solid surfaces is of great interest in diverse fundamental and industrial research. For studying such dynamics in a microsystem, existing investigations mainly focus on sorption behaviors mediated by external temperature variations. Here, we demonstrate a route to in situ sensitive detection of laser irradiation-induced localized water molecule desorption at a sub-monolayer level on an oxide surface. Harnessing a tailored set of optical whispering-gallery-mode (WGM) resonances in a nanomembrane-based microtube cavity, the desorption can be tracked by resonance mode shift in real-time, and further explained using a combination of pseudo-first-order and pseudo-second-order models. Additionally, upon adjusted laser excitation locations, the axial-mode-dependent responses enable the retrieval of corresponding profiles of desorption-induced perturbation at equilibrium. This study provides new insights into molecular desorption kinetics and introduces a spatially resolved sensing technique with applications in surface science, molecular sensing, and the study of desorption dynamics at the nanoscale.
理解水分子与各种固体表面之间的吸附动力学在众多基础研究和工业研究中都备受关注。对于在微系统中研究此类动力学，现有研究主要集中在由外部温度变化介导的吸附行为上。在此，我们展示了一种在氧化物表面亚单层水平原位灵敏检测激光辐照诱导的局部水分子解吸的方法。利用基于纳米膜的微管腔中一组定制的光学回音壁模式（WGM）共振，解吸过程可通过共振模式的实时位移进行跟踪，并结合伪一级和伪二级模型进行进一步解释。此外，通过调整激光激发位置，轴向模式相关的响应能够获取平衡时解吸诱导扰动的相应分布。本研究为分子解吸动力学提供了新的见解，并引入了一种空间分辨传感技术，可应用于表面科学、分子传感以及纳米尺度解吸动力学的研究。
