Current Research
Surface acoustic wave biosensors
Wave-guided Love waves for biomarker quantification and Rayleigh waves for acoustic mixing and removal of non-specifically bound proteins are launched orthogonally on the same piezoelectric substrate ST-quqrtz for real-time, label-free quantification of biomarkers directly from a complex biofluid such as blood in a clinically-relevant time-frame--- a few minutes at sub-ng/ml levels. A noise-cancelling delay-line effectively removers environmental noise and thermal drift due to acousto-thermal heating during the Rayleigh wave mixing process. It is demonstrated by accurately quantifying a cancer biomarker carconoembryonic antigen (CEA) from human plasma at clinically-relevant pg-ng/ml concentrations.
Sample generation for mass spectrometry
Samples for mass spectrometric analysis are generated using by combining surface acoustic wave nebulization (SAWN) with ionizaion using non-thermal plasma generated by techniques such as dielectric barrier discharge ionization (DBDI) and piezoelectric direct discharge (PDD), or corona discharge. SAWs are also utlized to disrupt bilayer vesicles such as extracellular vesicles including exosomes, lyse cells, and disrupt protein aggregates, all of which are directly analyzed using mass spectrometry. Advantages of this new approach to MS sample generation include ability to analyze very small samples, superior fragmentation characteristics, and better sensitivity compared to the gold standard electrospray ionization. In addition, this approach allows for the ranalysis of aggregated bodies such as proteins, allowing for analysis of membrane proteins for example, and analysis if the cargo of exosomes, of medical importance.
This work is in close collaboration with Analytical Chemistry Professor Theresa Evans-Nguyen.
Perovskite oxides for chemical conversion
Pervoskite oxides and other multicomponent oxides are synthesized at scale using a new liquid phase atomic layer deposition (LALD) technique to demonstrate much larger surface areas, and template-free atomically precise depositon. Metal atoms are then deposited at single atom dispersion level to produce catalyst materials. ABO3 perovsites deposited on Al2O3 were shown to exhibit an order of magnitude enhancement in CO yield and a similar increase in CO formation rate compared to typical sol-gel-derived pervoskites in a scalable reverse water gas shift chemical looping (RWGS-CL) process, as an example. Earth abundant perovskites were identified in DFT screening studies for this process, which has now been developed to pilot-scale, and is in demonstration phase at Tampa Electric Company using CO2 from their natural gas power plant. The combined use of electronic structure calculations, statistical mechanical theory, LALD synthesis, experimental characterization, and reactor studies is expected to yield high-performing materials and catalysts from this research.
This work is in close collaboration with Chemical Engineering Catalysis Professor John Kuhn.