Persistent Luminescence and in Vivo Bioimaging

In vivo bioimaging encompasses the non-invasive visualization of internal cells or organs within the human body, facilitating the real-time monitoring of dynamic biological processes. This form of bioimaging holds paramount significance within clinical domains due to its capacity to facilitate early disease detection, notably in cases of life-threatening conditions such as cancer. Although established imaging modalities like ultrasound, magnetic resonance imaging, and fluorescence imaging exist, the quest for innovative imaging probes with enhanced visibility to provide high-resolution images remains an active area of research. The introduction of persistent luminescent nanoprobes, characterized by their unique afterglow luminescence property, presents an exciting avenue in the realm of bioimaging. These nanoprobes offer several advantages over traditional fluorescent probes, notably in their ability to surmount light attenuation challenges within biological tissues including issues such as autofluorescence and light scattering. The chapter offers a succinct introduction to two pivotal facets of fluorescence imaging, namely persistent luminescence and upconversion luminescence while elucidating the underlying mechanisms governing their luminescence behavior. Moreover, this chapter provides comprehensive insights into various fluorescence imaging techniques, encompassing near-infrared imaging, upconversion imaging, X-ray-activated luminescence imaging, persistent luminescence imaging, and various multimodal imaging techniques.