Self-powered and transparent all-graphene biosensor

We propose here the design and concept of self-powered wireless sensor based on the graphene radio-frequency (RF) components, which are transparent, flexible, and monolithically integrated on biocompatible soft substrate. This all-graphene wireless sensor consists of an optically transparent graphene antenna, which receives the fundamental tone and retransmits the sensed signal at its second harmonic, thus allowing low-noise sensing in a severe interference/clutter background. We show that a quad-ring circuit based on graphene transistors may simultaneously offer sensing and frequency modulation functions, with the nonlinear conversion gain being chemically sensitive to the gas/molecular/chemical exposures and agents. This battery-free and transparent sensors based on newly discovered 2D nanomaterials may benefit versatile wireless sensing and internet-of-things applications, such as smart contact lenses/glasses and microscope slides.