▎ 摘　　要

NOVELTY - Detecting one or more drugs and/or drug metabolites of interest in a liquid sample involves providing a device, the device comprising a graphene field effect transistor and a first aptamer coupled to the graphene field effect transistor, the first aptamer is selective for a first drug or drug metabolite of interest; exposing a liquid sample to the first aptamer of the device; then, applying a liquid gate voltage to the device and measuring the resultant resistance; and comparing the resultant resistance to appropriate standards to determine the presence and/or quantity of the first or metabolite of interest. USE - Method for detecting one or more drugs and/or drug metabolites of interest in liquid sample. ADVANTAGE - The method is a portable, hand-held instrument that may include data storage and wireless communications for real-time dissemination of actionable data. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a device for use in detecting one or more drugs and/or drug metabolites of interest in a liquid sample which comprises a graphene field effect transistor, the graphene field effect transistor comprising a first well; and a first aptamer, the first aptamer being coupled to the graphene field effect transistor in the first well, the first aptamer being selective for a first drug or drug metabolite of interest; and (2) a system for detecting one or more drug and/or drug metabolites in a liquid sample, comprises a voltage sweep generator for applying a voltage sweep to the graphene field effect transistor, and a reader/analyzer for measuring the resultant resistance and comparing the resultant resistance to appropriate standards.