Mixed gold and platinum nanostructured layers for all-solid-state ion sensors

The great interest in portable and wearable monitoring systems has promoted in recent years a major expansion of all-solid-state Ion-Selective Electrodes (ISEs). Nanostructured Solid-Contacts (SCs) have shown a promising potential in order to eliminate the inherent potential drift of these systems. Notably the use of nanostructured layers offers some considerable advantages with respect to conductive polymers thanks to their hydrophobic behaviour, large surface area and absence of side-reactions. In this work, we develop for the first time mixed gold and platinum nanostructured SCs which show among the highest capacitance values reported in literature, while allowing a simple and fast (less than 6 minutes) deposition by electrochemical means. Cyclic Voltammetry (CV) and Current Reversal Chronopotentiometry (CRC) were employed to characterize the high performance and potential stability of these systems. The fabrication and calibration of Li+ ISEs corroborate the possibility to use these novel SCs to build highly stable and accurate ion sensors.