Self-powering amperometric sensor and biosensor

A unique Prussian blue nanotubes sensor using a two-compartment cell derives the current signal from the chemical energy of the hydrogen peroxide analyte, without input of electrical potentials, is described. The Prussian blue reduces hydrogen peroxide and is itself reduced by electron flow from the counter reaction at the auxiliary electrode. The concentrations of the Prussian blue (PB) and Everitt’s salt (ES) forms of the Prussian blue are maintained at steady-state values, by the hydrogen peroxide reduction and the galvanic cell reaction. This strategy gives low detection limit of 0.1 μM H2O2 with linear range up to 80 μM and is further demonstrated in a model glucose biosensor. The simple design to reduce energy usage opens up the study of amperometric sensor development by selecting anodic and cathodic reactions with suitable thermodynamic potentials with consideration of reactions at the sensing and auxiliary electrodes modified with appropriate mediators or enzymes.