Ultrasensitive quartz crystal microbalance with porous gold electrodes

The quartz crystal microbalance is a sensitive thickness monitor used in a variety of technological applications. It is also a versatile research tool for chemical sensor, nanotribology, wetting transition, and superfluid transition studies. By replacing the conventional gold electrodes with porous gold electrodes, the effective adsorbing surface area and hence sensitivity was enhanced by a factor of 40 with no sacrifice of the mechanical quality factor or the stability in the resonant frequency. (C) 2004 American Institute of Physics.