Quantum Dots: Catalysts for a New Era of Precision Medicine and Biomedical Innovation

Quantum dots have emerged as transformative nanomaterials whose extraordinary optical and electronic properties are revolutionizing precision medicine and biomedical innovation. This comprehensive review synthesizes multidisciplinary advances from cutting-edge eco-friendly and biogenic synthesis methods to sophisticated surface modification strategies such as ligand engineering, zwitterionic polymer coatings, and congeneric passivation, which together increase biocompatibility, reduce nonspecific binding, and prolong in vivo circulation. We explore the development of multifunctional hybrid nanocomposites, including QD-gold nanostars and QD/MoS₂ systems, which exhibit remarkable performance in multimodal imaging, fluorescence-guided surgery, and smart drug delivery applications. Furthermore, this review highlights the pivotal role of QDs in photothermal and photodynamic therapies, where their capacity to convert light into localized therapeutic effects paves the way for innovative cancer and dental treatments. Emphasis is placed on the integration of QDs as traceable carriers for targeted drug delivery, enabling real-time monitoring and controlled release via pH-sensitive and enzyme-responsive systems. Despite persistent challenges such as scalability, reproducibility, and concerns over heavy metal toxicity, ongoing interdisciplinary research is steadily overcoming these hurdles. By merging innovative synthesis, precise surface engineering, and strategic hybridization, QDs are positioned as critical components of next-generation diagnostic and therapeutic platforms that promise personalized, minimally invasive, and highly effective treatment modalities.