Recent advances in synthesis and application of organic near-infrared fluorescence polymers

Biofluorescence imaging enables real-time, visual detection of biomolecules, cells and tissues/organs on a three-dimensional scale. And it can track the various physiological processes of the organism and understand the relationship between biomolecules and their structure and function. Near-infrared imaging has a high temporal and spatial resolution, low damage to biological tissues and strong penetrating capability, good sensitivity and low background fluorescence interference, which are the advantages of imaging technology. However, at present, the deficiencies of fluorescent groups include relatively low fluorescence quantum yield and unfavorably short emission wavelength in the NIR region, especially in the second near-infrared window (1000–1700 nm, NIR-II). In the in vivo processes and applications of NIR fluorescence materials, biocompatibility, fluorescence quantum efficiency and adjustability of excitation and emission wavelengths in the NIR region should be considered. Therefore, organic polymeric materials are ideal for the construction of the NIR fluorescence probe. In this review, the synthesis and applications of NIR fluorescence polymers were summarized and the future trend has prospected as well.