Metal pillar device structures and methods for making and using them in electrochemical and/or electrocatalytic applications

An electrode useful in an analyte sensor, comprising:

• a base substrate comprising an insulative material;
• and
• a working electrode comprising a sputtered metal composition formed into pillars by sputter depositing material onto the base substrate, the sputtered metal composition sputtered by ionized gas particles having a pressure greater than a threshold pressure and accelerated by at least one of an electric or magnetic field to collide with a target so as to project metal composition from the target into a shape of the pillars on the base substrate;
• wherein the pillars disposed on the base substrate each:
• consist essentially of the sputtered metal composition forming an electroactive surface of the working electrode,
• have a height up to 10 micrometers, and
• have a diameter in a range of 1 nanometer-1000 nanometers;
• an analyte sensing layer disposed directly on the pillars, the analyte sensing layer comprising an oxidoreductase enzyme reacting with glucose to produce hydrogen peroxide;
• and
• an analyte modulating layer disposed over the analyte sensing layer, wherein the analyte modulating layer comprises a glucose limiting membrane that modulates a diffusion of the glucose therethrough.