  Simpler and more rapid approaches for therapeutic drug-level monitoring are
highly desirable to enable use at the point-of-care. We have developed an
all-electronic approach for detection of the HIV drug tenofovir based on
scalable fabrication of arrays of graphene field-effect transistors (GFETs)
functionalized with a commercially available DNA aptamer. The shift in the
Dirac voltage of the GFETs varied systematically with the concentration of
tenofovir in deionized water, with a detection limit less than 1 ng/mL. Tests
against a set of negative controls confirmed the specificity of the sensor
response. This approach offers the potential for further development into a
rapid and convenient point-of-care tool with clinically relevant performance.
