可激活的NIR-Ⅱ探针用于肿瘤成像

The near-infrared window with a wavelength between 1000 and 1700 nm is usually called the second near-infrared (NIR-Ⅱ) window. In terms of biological imaging (fluorescence imaging, photoacoustic imaging, etc.), this window shows a strong attraction. Compared with traditional imaging in the visible light (400~700 nm) region and the first near-infrared (NIR-Ⅰ 700~900 nm) window, NIR-Ⅱ bioimaging provides the advantages of high resolution and deep penetration depth. However, most current "always-on" probes cannot achieve a higher signal-to-noise ratio. The imaging of tumor microenvironment-responsive smart drugs is only triggered in tumors, which can overcome this limitation. Therefore, the tumor microenvironment and the NIR-Ⅱ intelligent response probe should be fully combined, and the advantages of both will be fully utilized to improve the accurate diagnosis of tumors. This article reviews the latest research progress of activatable NIR-Ⅱ fluorescent probes in bioimaging from different pathological parameters, and presents views on the opportunities and challenges faced by this emerging field.