Medical diagnostics is an industry that is expanding rapidly, with the global biosensor market expected to exceed $US18 billion by 2018. Electrochemical biosensors, as exemplified by the blood glucose monitor, have the potential to revolutionise medical diagnostics and patient monitoring. They offer cheap, automated and easy-to-handle platforms which combine sample processing and analysis to give a read-out in minutes. Impedimetric biosensors are enormously attractive medically, as they offer a rapid, portable, inexpensive and highly sensitive test that can be performed at the point-of-care by a non-specialist user.