Optics and Photonics, Faculty of Engineering, University of Nottingham, University Park, Nottingham, UK.
Sci Rep. 2021 Feb 8;11(1):3301. doi: 10.1038/s41598-021-82639-w.
Brillouin light scattering (BLS) is an emerging method for cell imaging and characterisation. It allows elasticity-related contrast, optical resolution and label-free operation. Phonon microscopy detects BLS from laser generated coherent phonon fields to offer an attractive route for imaging since, at GHz frequencies, the phonon wavelength is sub-optical. Using phonon fields to image single cells is challenging as the signal to noise ratio and acquisition time are often poor. However, recent advances in the instrumentation have enabled imaging of fixed and living cells. This work presents the first experimental characterisation of phonon-based axial resolution provided by the response to a sharp edge. The obtained axial resolution is up to 10 times higher than that of the optical system used to take the measurements. Validation of the results are obtained with various polymer objects, which are in good agreement with those obtained using atomic force microscopy. Edge localisation, and hence profilometry, of a phantom boundary is measured with accuracy and precision of approximately 60 nm and 100 nm respectively. Finally, 3D imaging of fixed cells in culture medium is demonstrated.
布里渊光散射（BLS）是一种新兴的细胞成像和特性分析方法。它可以提供与弹性相关的对比度、光学分辨率和无标记操作。声子显微镜通过激光产生的相干声子场来检测 BLS，为成像提供了一种有吸引力的途径，因为在 GHz 频率下，声子波长小于光学波长。使用声子场来对单细胞成像具有挑战性，因为信号噪声比和采集时间通常较差。然而，仪器的最新进展使得对固定和活细胞的成像成为可能。这项工作首次对基于声子的轴向分辨率进行了实验表征，该分辨率是通过对锐边响应获得的。所获得的轴向分辨率比用于进行测量的光学系统高 10 倍以上。使用各种聚合物物体对结果进行了验证，与使用原子力显微镜获得的结果吻合良好。通过大约 60nm 和 100nm 的精度和准确度测量了幻影边界的边缘定位和轮廓测量。最后，展示了培养介质中固定细胞的 3D 成像。
