Project Summary
Our research program focuses on the development of analytical tools to enhance the characterization of complex
biological systems. For rapid, real-time analysis of these systems, sensors based on spectroscopic,
electrochemical, and mass spectrometric detection have been widely utilized. However, the capability of these
approaches to simultaneously monitor multiple analytes suffers without the use of chemical separations. To
achieve sensor-like performance with a separations-based platform, this project focuses on the creation of a
liquid chromatography-mass spectrometry (LC-MS) platform for near-universal, real-time online measurement
of targeted small molecule metabolites. High-throughput gradient LC separations at capillary-scale flow rates will
be achieved through system miniaturization and improved microfluidic mixing combined with a droplet-based
injection approach. Improved analyte selectivity and sensitivity for targeted metabolites will be achieved with an
online benzoyl chloride derivatization device. To improve the temporal resolution of sampling, the derivatization
technique will be adapted to a segmented flow droplet format. Dual column re-equilibration will further increase
throughput by 20%, achieving an overall method cycle time of 10-15 s. By combining these fundamental
advances in separation science, a transformational measurement platform will be achieved. The system will be
used to specifically probe: (1) neurotransmitter release from organoid cell models of traumatic brain injury, (2)
polyamine secretion during bacterial biofilm formation, and (3) cell culture media nutrient depletion observed
during therapeutic antibody manufacturing.