Chick, ShannonKachouei, Matin AtaeiKnowlton, KatharineAli, Md. Azahar2024-10-242024-10-242024-08-22https://hdl.handle.net/10919/121382Precision livestock farming utilizing advanced diagnostic tools, including biosensors, can play a key role in the management of livestock operations to improve the productivity, health, and well-being of animals. Detection of ketosis, a metabolic disease that occurs in early lactation dairy cows due to a negative energy balance, is one potential on-farm use of biosensors. Betahydroxybutyrate (βHB) is an excellent biomarker for monitoring ketosis in dairy cows because βHB is one of the main ketones produced during this metabolic state. In this report, we developed a low-cost, Keto-sensor (graphene-based sensor) for the detection of βHB concentrations in less than a minute. On this device, graphene nanosheets were layered onto a screen-printed electrode (SPE), and then, a stabilized enzyme (beta-hydroxybutyrate dehydrogenase, NAD⁺, and glycerol) was used to functionalize the graphene surface enabled by EDC−NHS conjugation chemistry. The Keto-sensor offers an analytical sensitivity of 10 nM and a limit of detection (LoD) of 0.24 nM within a detection range of 0.01 μM−3.00 mM. Spike testing indicates that the Keto-sensor can detect βHB in serum samples from bovines with subclinical ketosis. The Keto-sensor developed in this study shows promising results for early detection of subclinical ketosis on farms.application/pdfenAttribution 4.0 InternationalPrecision livestock farmingSubclinical ketosisBiosensorGrapheneStabilized enzymeArticle - Refereedhttps://doi.org/10.1021/acsami.4c07715.s0011639