AIE Nanoprobes for NIR‐II Fluorescence In Vivo Functional Bioimaging

The development of biological imaging has been promoted by proposal of aggregation-induced emission (AIE). According to Rayleigh scattering theory, longer wavelength means lower tissue scattering, leading to large imaging depth. Compared with traditional near-infrared (NIR)-I (760–900 nm) region, fluorescence imaging in the second NIR window (NIR-II, 900–1880 nm) theoretically affords deep tissue penetration and sharp resolution, holding a great promise for mammal imaging. The AIE phenomenon is ideal for the design of many bright deep-red or NIR emission probes, meeting the tremendous demand of the organic NIR-II bioprobes. In this chapter, a focused overview on the current applications of AIE-assisted fluorescence imaging in vivo is presented. Perspectives on the challenges and opportunities facing this nascent yet exciting field are then given.