A biosensor system comprises a capillary substrate, conductive electrode, and a plurality of nanoparticles having an enzyme deposited thereon formed in a cavity at one end of the capillary substrate. The substrate may have an optional reinforcing layer (which may be conductive or non-conductive) and optional insulating layer thereon. A cannula having an optional conductive layer, insulating layer, and reference electrode may also form part of the system.
