Electrospray from Nanostructured Tungsten Oxide Surfaces with Ultralow Sample Volume

This study demonstrated the feasibility of performing protein analysis with ultralow sample volume by combining a tungsten oxide nanowire (TON) fiber with a miniaturized electrospray ionization interface. An increase in wettability of the tugsten surface after growing randomly oriented TON on its surface allows strong adhesion of approximately 50 nL of the methanol solution at its tip. Under the influence of a high electric field, electrospray from a Taylor cone on the adhered methanol solution was observed and the multiply charged ions of protein molecules predissolved in the solution were detected.