Rational Design of Near‐infrared II Plasmonic Optofunctional Materials for Diagnostic and Therapeutic Applications

Plasmonic materials have aroused considerable interest in diagnostic and therapeutic biomedical applications because of their remarkable optical properties and the integration of multiple functionalities. Particularly, near‐infrared II (NIR‐II) plasmonic materials present great advantages for anticancer treatments, including deep tissue penetration, low tissue light scattering and autofluorescence, and high spatial resolution. Thus, NIR‐II plasmonic phototheranostics represents a promising approach for effective anticancer treatments through multi‐modal imaging‐guided therapy. Accordingly, tremendous efforts have recently been devoted to the development of NIR‐II plasmonic materials for highly efficient phototheranostics. In this review, the recent progress of NIR‐II plasmonic materials and their phototheranostic applications are overviewed. First, the localized surface plasmon resonance effect and the related optical properties such as the photothermal effect, photoacoustic effect, and surface‐enhanced Raman scattering (SERS) effect are introduced. Then, the unique features and the structure‐property relationship of various types of NIR‐II plasmonic materials are discussed. Finally, the recent progress of NIR‐II plasmonic material‐based multimodal phototheranostics with an emphasis on the integration of multiple functionalities are reviewed, and subsequently the current challenges and future research perspectives are discussed. This review will provide valuable guidelines for the rational design of NIR‐II plasmonic materials for highly efficient cancer phototheranostics in the future.