Abstract: Systems and methods of functionalizing a graphene sensor surface are provided. A representative method of functionalizing the graphene sensor surface includes providing a graphene layer including a sensor surface. The method may include binding a plurality of molecular complexes to the sensor surface of the graphene layer using a buffer solution. Each molecular complex may include a linker molecule configured to couple to the sensor surface at a first linker position, and a binding molecule coupled to the linker molecule at a second linker position different from the first linker position. The representative method further includes coupling one or more detector molecules to a first subset of the molecular complexes and coupling one or more passivation agents to a second subset of the molecular complexes. At least some of the molecular complexes of the first subset are different from those of the second subset.

Abstract: In one aspect, a sample collection device for collecting a biological sample is disclosed, which comprises a sample-receiving cup having a body that extends from a proximal opening to a distal opening, where the proximal opening is configured for receiving a biological sample. The sample collection device further includes a sensor comprising at least one sensing unit, where the sensor is sealingly connected to the distal opening of the sample-receiving cup such that the sensing unit is exposed to the distal opening. A reservoir for storing one or more sample-processing reagents is provided in the fluid-receiving cup such that the sensing unit is in fluid contact with the reagent(s) stored in the reservoir. A frangible membrane separates the reservoir from the proximal opening.