This review article by Varnakavi Naresh and Nohyun Lee from Kookmin University, Seoul, Korea, provides an overview of biosensors and the recent advancements in nanostructured materials-enabled biosensors. Biosensors are integrated devices that convert biological responses into electrical signals, with applications in healthcare, disease diagnosis, environmental monitoring, and drug delivery. The main challenges in biosensor development include efficient signal capture, transduction, and miniaturization. These challenges can be addressed through the integration of nanomaterials, which offer high surface-to-volume ratios, good conductivities, and tunable properties. The review covers the evolution of biosensors, types based on receptors and transducers, and modern approaches using nanomaterials such as nanoparticles, nanowires, carbon nanotubes, and quantum dots. It also discusses the characteristics, classification, and immobilization techniques of biosensors, as well as the principles and applications of different types of transducers, including electrochemical, optical, thermal, electronic, and gravimetric biosensors. The article highlights the advancements in biosensing technology driven by nanotechnology and the potential of nanomaterials in enhancing biosensor performance.This review article by Varnakavi Naresh and Nohyun Lee from Kookmin University, Seoul, Korea, provides an overview of biosensors and the recent advancements in nanostructured materials-enabled biosensors. Biosensors are integrated devices that convert biological responses into electrical signals, with applications in healthcare, disease diagnosis, environmental monitoring, and drug delivery. The main challenges in biosensor development include efficient signal capture, transduction, and miniaturization. These challenges can be addressed through the integration of nanomaterials, which offer high surface-to-volume ratios, good conductivities, and tunable properties. The review covers the evolution of biosensors, types based on receptors and transducers, and modern approaches using nanomaterials such as nanoparticles, nanowires, carbon nanotubes, and quantum dots. It also discusses the characteristics, classification, and immobilization techniques of biosensors, as well as the principles and applications of different types of transducers, including electrochemical, optical, thermal, electronic, and gravimetric biosensors. The article highlights the advancements in biosensing technology driven by nanotechnology and the potential of nanomaterials in enhancing biosensor performance.