Engineering Photothermal Nanoplatforms for Multimodal Theranostics and Biosensing

Photothermal platforms bridge materials science and biomedicine, emerging as a transformative frontier in biomedical applications. They offer spatiotemporally precise, noninvasive modalities with cell‐type‐independent efficacy for treating a range of diseases. This review systematically examines the fundamental mechanisms of photothermal conversion, including plasmonic heating, nonradiative relaxation in semiconductors, and molecular thermal vibrations. Key strategies for enhancing light harvesting, heat generation, and thermal management are discussed, with emphasis on nanostructure engineering, doping, assembly, and surface functionalization. Quantitative models for evaluating photothermal efficiency and heat transfer are presented. The article highlights cutting‐edge applications in cancer therapy, biosensing, and antibacterial treatments. Finally, current challenges and future directions toward clinical translation are addressed, providing a comprehensive perspective on synergistic photothermal nanomedicine.