Optoelectromechanical multimodal biosensor with graphene active region.

A general, overarching theme in nanotechnology is the integration of multiple disparate fields to realize novel or expanded functionalities. Here, we present a graphene enabled, integrated optoelectromechanical device and demonstrate its utility for biomolecular sensing. We experimentally achieve an ultrawide linear dynamic sensing range of 5 orders of magnitude of protein concentration, an improvement over state-of-the-art single mode nanosensors by approximately 2-3 orders of magnitude, while retaining a subpicomolar lowest detection limit. Moreover, the ability to monitor and characterize adsorption events in the full optoelectromechanical space allows for the extraction of key intrinsic parameters of adsorbates and has the potential to extend the capabilities of nanosensors beyond the traditional binary-valued test for a single type of molecule. This could have significant implications for molecular detection applications at variable concentrations, such as early disease detection in biomedical diagnostics.