Electrical biosensors and the label free detection of protein disease biomarkers

Electrical detection methodologies are likely to underpin the progressive drive towards miniaturised, sensitive and portable biomarker detection protocols. In being easily integrated within standard electronic microfabrication formats, and developing capability in microfluidics, the facile multiplexed detection of a range of proteins in a small analytical volume becomes entirely feasible with something costing just a few thousand pounds and benchtop or handheld in scale. In this review, we focus on recent important advances in label free assays of protein using a number of electrical methods, including those based on electrochemical impedance spectroscopy (EIS), amperometry/voltammetry, potentiometry, conductometry and field-effect methods. We introduce their mechanistic features and examples of application and sensitivity. The current state of the art, real world applications and challenges are outlined.