Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, 920-1192, Japan.
Division of Electric Engineering and Computer Science, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.
Sci Rep. 2020 Oct 15;10(1):17436. doi: 10.1038/s41598-020-74433-x.
In recent years, the atomic force microscope has proven to be a powerful tool for studying biological systems, mainly for its capability to measure in liquids with nanoscale resolution. Measuring tissues, cells or proteins in their physiological conditions gives us access to valuable information about their real 'in vivo' structure, dynamics and functionality which could then fuel disruptive medical and biological applications. The main problem faced by the atomic force microscope when working in liquid environments is the difficulty to generate clear cantilever resonance spectra, essential for stable operation and for high resolution imaging. Photothermal actuation overcomes this problem, as it generates clear resonance spectra free from spurious peaks. However, relatively high laser powers are required to achieve the desired cantilever oscillation amplitude, which could potentially damage biological samples. In this study, we demonstrate that the photothermal excitation efficiency can be enhanced by coating the cantilever with a thin amorphous carbon layer to increase the heat absorption from the laser, reducing the required excitation laser power and minimizing the damage to biological samples.
近年来，原子力显微镜已被证明是研究生物系统的有力工具，主要是因为它能够在纳米尺度的液体环境中进行测量。在生理条件下测量组织、细胞或蛋白质，使我们能够获得有关其真实“体内”结构、动态和功能的有价值信息，从而推动医学和生物学的突破性应用。原子力显微镜在液体环境中工作时面临的主要问题是难以产生清晰的悬臂共振谱，这对于稳定操作和高分辨率成像至关重要。光热激励克服了这个问题，因为它产生了清晰的共振谱，没有杂峰。然而，为了达到所需的悬臂振荡幅度，需要相对较高的激光功率，这可能会潜在地损坏生物样本。在这项研究中，我们证明通过在悬臂上涂覆一层薄的非晶碳层可以提高光热激励效率，从而增加激光的热吸收，降低所需的激励激光功率，并最小化对生物样本的损伤。
