2D nanomaterials for near infrared responsive photomedicine: a review

The continuously growing demand for efficient and non-invasive treatment has accelerated the development of near infrared (NIR) responsive phototherapy, a therapeutic modality that leverages the biological transparent window (700-1850 nm) to enable deeper tissue penetration compared to ultraviolet (UV)/visible light approaches. NIR-responsive two-dimensional (2D) nanomaterials have emerged as particularly promising platforms for advanced photomedicine, attributed to high surface-to-volume ratio, tunable electronic structure, and broadband optical absorption. 2D nanomaterials can be broadly classified into elemental materials, layered nonmetal compounds, metal-based compounds, and 2D organic frameworks, each exhibiting distinct physicochemical and photonic features that enable tailored photothermal and photodynamic therapy applications. Their structural versatility and surface functionality further facilitate multimodal NIR theranostic integration. This review systematically investigates recent advances in NIR-responsive 2D nanomaterial-mediated phototherapy, with particular emphasis on their photomedical performance. Furthermore, the existing critical challenges, including biocompatibility, long-term biosafety, controlled degradation, NIR penetration depth limitations, and clinical translation barriers have been overviewed. Finally, future perspectives are proposed to guide the development of the next-generation NIR-responsive 2D nanomaterials for photomedicine.