With recent advances in nanotechnology, development of nanomaterial bioconjugates is growing exponentially towards eventual translation into biomolecular recognition layers on surfaces. Label-free monitoring of biorecognition events is also key-technology and provides a promising platform, which is simple, cost-effective, and requires no external modification to biomolecules. In this review, we describe the application of nanomaterials, mainly metal nanoparticles, and specific applications of carbon nanotubes (CNTs) based label-free approaches.