Emerging metallic nanotechnology platforms for cancer sensing and imaging

Despite major advances, the management of cancer remains one of the greatest unresolved challenges in medicine and a leading cause of death worldwide. Thus, improved, early, and minimally invasive diagnostics are urgently demanded. In recent years, extraordinary progress in nanotechnology has radically changed this situation by providing unprecedented molecular-level insight into cancer cell mechanisms through highly sensitive biosensing platforms and multifunctional nanoprobes for advanced imaging. This review offers a unique perspective on emerging nanotechnology-based cancer diagnostics by examining the interconnected development of sensing and imaging technologies through the lens of nanomaterial physicochemical properties. In sensing, we highlight recent breakthroughs in electrochemical, optical, photoelectrochemical (PEC), enzymatic, surface-enhanced Raman scattering (SERS)-based, electroluminescence-PEC hybrid, molecular, fuel cell-powered, and nanocatalytic biosensing strategies. These approaches enable ultrasensitive and selective detection of a wide range of circulating biomarkers, including microRNAs (miRNAs), extracellular vesicles (EVs), exosomes, cell-free DNA, oncogenes, circular RNAs, circulating tumor cells (CTCs), telomerase activity, circulating proteins, methylation patterns, and tumor-associated carbohydrates. Beyond sensing, we also highlight significant advances in nanotechnology-based imaging, including magnetic resonance imaging (MRI), SERS, fluorescence, circular dichroism, and photoacoustic imaging. In these modalities, intelligent nanoprobes enhance specificity, resolution, and in vivo tissue imaging capabilities. Finally, we discuss the growing convergence of sensing and imaging nanotechnologies, the need for integrated theranostic platforms, translation into point-of-care devices, incorporation of artificial intelligence-driven analytics, and critical considerations related to nanobiomaterial safety. Collectively, these advances position nanotechnology as a transformative force in next-generation cancer diagnostics.