Photothermal Microimaging: A Non-Invasive and High-Resolution Imaging Technique

Super-resolution optical imaging technology has significant implications for biology, life science, and materials science. The mainstream technology to achieve super-resolution optical imaging relies on fluorescence imaging, but fluorescence- based super-resolution imaging cannot reveal molecular-specific information and causes cytotoxicity to living cells. In contrast, photothermal microscopy is a promising analytical technique that allows noninvasive imaging of molecular bonds. Therefore, photothermal microscopy can overcome the inherent limitations of super-resolution fluorescence imaging, making it an attractive option with excellent application prospects. This review discusses the theoretical basis of photothermal microscopy, development of the imaging technique, and the methodological developments that improve the detection limit and spatial resolution. We further provide future perspectives for promoting the development of high-sensitivity and super-resolution photothermal imaging technology.