Lead University: Carnegie Mellon University
PI: Nisha Shukla, Engineering Research Accelerator
Co-PIs: A.J.Gellman, Chemical Engineering

A new type of quartz crystal sensor will be developed for use in quartz crystal microbalance (QCM) systems used for detection of analytes in water-based systems and for enantiospecific adsorption of chiral pharmaceuticals. The sensor will be based on a standard quartz crystal but with electrodes manufactured from nanoporous gold (np-Au) rather than dense gold. The nanoporosity of the Au films increases their surface area by ~100-fold, and it has been demonstrated that this can increase QCM sensitivity by an order of magnitude (and probably by significantly more) over commercially available QCM systems. More importantly, the np-Au sensors to be developed in this PITA project will significantly improve the operation of QCMs for measurement of adsorption from liquids. QCM’s detect mass adsorbed onto smooth Au electrode surfaces by extremely sensitive measurement of shifts in the resonant frequency of the quartz crystal. In the presence of liquids, however, there are shifts in the frequency that also arise from dissipation due to the viscosity of the liquid. This complicates the analysis of adsorption. By using np-Au electrodes with much greater internal surface area than the flat electrodes, the dissipation issue is mitigated by the fact that the liquid is entrained in the nanoporous channels of the electrode. Successful completion of this project will result in the development of intellectual property that could be used as the basis for a small startup, or be value to existing commercial suppliers of QCM systems such as Oerlikon Leybold Vacuum in Export, PA and Kurt Lesker Co. in Pittsburgh, PA. The availability of these ultra-sensitive sensors will provide local researchers with capabilities that extend the current state of the art in detection of adsorption from solution and thereby, enhance the competitiveness of future research proposals in a wide variety of areas.