Marriage of a Dual‐Plasmonic Interface and Optical Microfiber for NIR‐II Cancer Theranostics

The use of light as a powerful tool for disease treatment has introduced a new era in tumor treatment and provided abundant opportunities for light-based tumor theranostics. This work reports a photothermal theranostic fiber integrating cancer detection and therapeutic functions. Its self-heating effect can be tuned at ultralow powers and used for self-heating detection and tumor ablation. The fiber, consisting of a dual-plasmonic nanointerface and an optical microfiber, can be used to distinguish cancer cells from normal cells, quantify cancer cells, perform hyperthermal ablation of cancer cells, and evaluate the ablation efficacy. Its cancer cell ablation rate reaches 89% in a single treatment. In vitro and in vivo studies reveal quick, deep-tissue photonic hyperthermia in the NIR-II window, which can markedly ablate tumors. The marriage of a dual-plasmonic nanointerface and an optical microfiber presents a novel paradigm in photothermal therapy, offering the potential to surmount the challenges posed by limited light penetration depth, nonspecific accumulation in normal tissues, and inadvertent damage in current methods. This work thus provides insight for the exploration of an integrated theranostic platform with simultaneous functions in cancer diagnostics, therapeutics, and postoperative monitoring for future practical applications.