Nanotechnology‐Enhanced Approaches for Early Cancer Diagnosis

ABSTRACT Early‐stage tumors often remain undetected because conventional diagnostic approaches, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), tissue biopsy, and liquid biopsy, frequently lack the sensitivity, molecular specificity, or comprehensive coverage required to identify microscopic lesions. Nanotechnology offers a unified framework to address these limitations. Engineered nanoparticles provide: (i) enhanced MRI, PET, and single photon emission computed tomography (SPECT) contrast through tunable magnetic, optical, or radionuclide payloads; (ii) selective tumor localization via antibody‐, peptide‐, or aptamer‐mediated targeting; and (iii) multimodal imaging outputs that enable real‐time visualization and image‐guided therapeutic decision‐making. Radiolabeled and magnetic nanoplatforms markedly improve lesion‐to‐background ratios, while nanoparticle‐enabled liquid biopsy strategies increase detection accuracy for scarce circulating biomarkers, including circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), exosomes, and tumor‐educated platelets (TEPs). Advances in biocompatible nanomaterials, such as carbon dots, graphene derivatives, and silicon‐based structures, and renal‐clearable surface chemistries further mitigate concerns regarding heavy‐metal toxicity and biodistribution. Collectively, these developments position nanoparticle technologies as essential tools for precise, minimally invasive, and personalized cancer diagnostics. This review examines how nanotechnology addresses the inherent limitations of conventional detection strategies, offering a sensitive, non‐invasive approach to early cancer diagnosis and clinical decision‐making.