Abstract: A sensor having improved shelf life is provided for determining concentration of a biomarker in a liquid sample. The sensor functions by electrochemical detection and requires use of a biomolecule, e.g., an enzyme that catalyzes an electron transfer reaction specific for the biomarker. The sensor requires use of a quaternary ammonium compound as a bio-linker. It further requires crosslinking of the biomolecule for improved stability.

Abstract: Novel devices and methods for rapid, liquid-based detection of viruses are provided, including rapid saliva-based detection of SARS-CoV-2. The devices can include one or more layers of graphene, and/or carbon nanotubes, nanoparticles, cross-linkers, redox probes, ACE2 enzyme, and aptamer or antibody (including SARS-CoV-2 antibody). Forward, and optionally reverse waveforms can be applied to the devices to provide voltammograms indicative of positive or negative detection of viruses.

Abstract: A device for treatment and collection of saliva provides a base containing aa suction source. A tip having an inlet for collecting a saliva sample is removably attached to the base. A filter material, selected to allow passage of a target biomarker in the saliva sample, is disposed within the tip on a fluid path from the inlet. A collection chamber is disposed on the fluid path downstream of the filter material. The suction source is in fluid communication with the fluid path to draw saliva into the inlet of the tip, through the filter material, and to the collection chamber. Methods for collection of a saliva sample are also provided.

Abstract: A sensor having improved shelf life is provided for determining concentration of a biomarker in a liquid sample. The sensor functions by electrochemical detection and requires use of a biomolecule, e.g., an enzyme that catalyzes an electron transfer reaction specific for the biomarker. The sensor requires use of a quaternary ammonium compound as a bio-linker. It further requires crosslinking of the biomolecule for improved stability.