NIR-II Fluorophores: From Synthesis to Biological Applications

• Published in: Journal of analysis and testing Vol. 7; no. 3; pp. 245 - 259
• Main Authors: Duo, You-Yang, Zhao, Liang, Wang, Zhi-Gang, Liu, Shu-Lin
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.09.2023
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Monitoring/Environmental Analysis; Review; Second near-infrared window; In-vivo imaging; Surgical navigation; Fluorophores; Phototherapy
• ISSN: 2096-241X; 2509-4696
• DOI: 10.1007/s41664-023-00254-2

Fluorescence imaging is a useful tool in the field of biomedical applications. However, its imaging capacity is limited by the depth of tissue that can be penetrated when using visible light (400–700 nm) or the first near-infrared window (NIR-I, 700–900 nm). To overcome the problem, fluorescence imaging in the second near-infrared window (NIR-II, 1000–1700 nm) has been developed to reduce photon scattering, auto-absorption and tissue autofluorescence to achieve high spatiotemporal resolution and deep imaging penetration. The key to NIR-II imaging is obtaining and analyzing highly selective information from functional fluorophores that emit in the 1000–1700 nm range. With the rapid development of multidisciplinary research, various types of NIR-II fluorophores have been produced and used in non-invasive, real-time NIR-II biomedical applications. This review summarizes some of the most prevalent NIR-II fluorophores and their synthesis, such as organic fluorophores (OFs), single-walled carbon nanotubes (SWCNTs), quantum dots (QDs), and rare-earth nanoparticles (RENPs). On this basis, we describe the applications of these fluorophores in biomedical fields, including bioimaging, biosensing, phototherapy and surgical navigation. Additionally, major challenges and prospects of NIR-II biomedical application will be further explored.