MIND-IN2UB, Departament d'Enginyeria Electrònica i Biomèdica, Facultat de Física, Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain.
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
Sci Rep. 2021 Apr 9;11(1):7829. doi: 10.1038/s41598-021-87558-4.
Optomechanical crystal cavities (OMC) have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, bacteria and viruses. In this work we demonstrate the working principle of OMCs operating under ambient conditions as a sensor of submicrometer particles by optically monitoring the frequency shift of thermally activated mechanical modes. The resonator has been specifically designed so that the cavity region supports a particular family of low modal-volume mechanical modes, commonly known as -pinch modes-. These involve the oscillation of only a couple of adjacent cavity cells that are relatively insensitive to perturbations in other parts of the resonator. The eigenfrequency of these modes decreases as the deformation is localized closer to the centre of the resonator. Thus, by identifying specific modes that undergo a frequency shift that amply exceeds the mechanical linewidth, it is possible to infer if there are particles deposited on the resonator, how many are there and their approximate position within the cavity region. OMCs have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, viruses and bacteria.
光机械晶体腔 (OMC) 在检测和间接分析生物粒子方面具有广阔的前景，例如蛋白质、细菌和病毒。在这项工作中，我们通过光学监测热激活机械模式的频率移动，展示了在环境条件下工作的 OMC 作为亚微米颗粒传感器的工作原理。该谐振器经过专门设计，使得腔区域支持特定的低模式体积机械模式家族，通常称为 -pinch 模式。这些模式只涉及几个相邻腔室的振动，它们对谐振器其他部分的干扰相对不敏感。这些模式的本征频率随着变形更靠近谐振器中心而降低。因此，通过识别经历频率移动的特定模式，该频率移动充分超过机械线宽，可以推断出在谐振器上是否沉积有颗粒、有多少颗粒以及它们在腔区域内的大致位置。光机械晶体腔在检测和间接分析生物粒子方面具有广阔的前景，例如蛋白质、病毒和细菌。
