Cancer remains a major threat to human health worldwide, but with progress in early diagnosis and treatment technology, the progression of cancer has been effectively slowed. Near-infrared (NIR) fluorescent probes are noninvasive imaging tools that show great promise for early tumor detection and intra-operative guidance due to their high sensitivity, deep tissue penetration, and high signal-to-noise ratio. In recent years, the rapid development of NIR fluorescent probes has been driven by a growing understanding of the unique characteristics of the tumor microenvironment. Targeting these features, such as pH, viscosity, polarity, hypoxia, and enzymes, has become a key strategy in the rational design of sensitive small-molecule fluorescent probes for cancer diagnosis and therapy. In this review, we have summarized the recent progress in NIR fluorescent probes for the tumor microenvironment, with an emphasis on their design principles, imaging performance, potential applications, and the challenges faced in clinical translation. Despite certain progress in near-infrared fluorescent probes, challenges remain, such as tumor heterogeneity and clinical translation. Future efforts should focus on multi-responsive designs, improved photostability, and multimodal imaging strategies. We hope this review can provide a valuable reference for the development of novel fluorescent probes.
Hu et al. (Thu,) studied this question.