Abstract: The present application relates to biosensors and methods for detecting and/or quantifying a target analyte such as a target allergen or toxin. In some embodiments, the biosensors use an allergen- or toxin-binding molecule conjugated to a fluorescent label such as a quantum dot that adheres to and is quenched by graphene oxide in the absence of the allergen or toxin.

Abstract: The present application relates to biosensors and methods for detecting and/or quantifying a target substrate. The biosensors comprise an electrode with a surface layer of tris-ruthenium bipyridine2+ complex modified graphene oxide and at least one enzyme linked to the surface layer.

Abstract: A method of detecting subclinical ketosis in a dairy animal comprises the steps of: obtaining a sample from the dairy animal, the sample containing one of a serum sample or a milk sample; incubating a mixture of the sample and a reactant containing NAD+-functionalized quantum dots to produce an incubated mixture; irradiating the incubated mixture with optical radiation of a first wavelength so as to emit fluorescent radiation of a second wavelength from the incubated mixture; irradiating a photodetector with the fluorescent radiation so as to generate an electrical signal; and performing data acquisition using the photodetector electrical signal to determine a BHBA concentration for the sample.