Collaborative Research: IDBR: Development of a Biofluid Transport, Separation and Molecular Analysis System using Microfluidics and a Miniature Mass Spectrometer

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Biological systems respond to environmental stresses and chemical agents by producing unique biochemical signatures, i.e. biomarkers, that - when detected and interpreted correctly - yield enormous insight into the state of the organism. Thus, the central objective of this work is to develop an integrated instrument that detects and identifies biomarkers by acquiring small- volume fluid samples, separating and pre-concentrating the biologically important components in a nanofluidic-microfluidic chip, and then characterizing them using on-line mass spectrometry in a miniature mass spectrometer. In the process, the applicability of molecular identification tools in biological research will be enhanced by significantly decreasing the concentration levels at which specific organic molecules can be detected in complex mixtures. Novel protocols for transferring and ionizing compounds of interest based on high-frequency ac electrospray ionization and desorption electrospray ionization methods will be developed and compared with respect to figures of merit, such as mass transfer efficiency, sensitivity and background interferences. One specific aim is to improve the efficiency of the ionization step, by far the least efficient process in mass spectrometry. Critical performance tests of the analysis system will target biomarkers for oxidative stress using biofluids which mimic cerebrospinal fluid (CSF). The coupling of micro/nano fluidic sample preparation to miniature atmospheric pressure mass spectrometers offers much value to the biological sciences, for example making it possible to realize real-time functional assays of changes in fundamental metabolic, regulatory and signaling processes in response to environmental factors. Fundamental improvements in the performance of mass spectrometers and in microfluidic devices will result from the synergy of this project, making possible future generations of biological instruments of great power and utility. In addition to the direct relevance to biological research, successful instrumentation development will impact medical diagnostics: The same markers relevant to biological oxidation processes are germane to the early detection and prognosis in a host of diseases, including multiple sclerosis, Alzheimer's disease, Niemann-Pick C, amyotrophic lateral sclerosis, heart disease, Parkinson's disease and ischemic stroke, making the results readily translatable to human health studies. Furthermore, the training of highly skilled instrumentation scientists is an emerging national need, and this need will be addressed by formalizing collaboration through (1) research student exchange between Notre Dame and Purdue and (2) larger scale exchanges between Purdue's Center for Analytical Instrumentation Development (CAID) and Notre Dame's Advanced Diagnostics and Therapeutics Initiative. Both institutions aim to (i) train graduate students in instrumentation science (ii) engage in instrumentation development, (iii) facilitate its commercialization, (iv) benefit the regional economy through instrument commercialization. The public can follow these activities at the relevant websites: http://sri.nd.edu/advanced-diagnostics- and-therapeutics/ and www.purdue.edu/dp/caid/.