Recent advances in Raman probes for multiplexed bioimaging

Bond-selective vibrational imaging techniques, such as Raman spectroscopy, are opening up many applications that were previously considered impossible or inaccessible by other means, such as fluorescence imaging. In particular, vibrational microscopy offers unique advantages, such as the ability to perform highly multiplexed, label-free imaging. Indeed, recent advances in optical and chemical technologies have made it possible to image biological phenomena at the cellular level with high sensitivity, high resolution, and high specificity. Applications of vibrational microscopy both in biological research and in medicine, including the detection of pathological lesions, are expanding rapidly. Here, we provide a general overview of Raman microscopy, and we review recent progress in cutting-edge applications, including label-free imaging and the development of small Raman tags, Raman probes enabling highly sensitive ultra-multiplexed observation, and functional Raman probes.