Tractable Tandem Ion Mobility Technology using Structures for Lossless Ion Manipulations and Photodissociation

Project Summary In addition to concentration, the orientation and conformation of proteins, carbohydrates, metabolites, and nucleic acids are essential characteristics differentiating healthy and diseased states. In fact, broadly available advances in mass spectrometry (MS), with unparalleled levels of selectivity, speed, and sensitivity, have armed

researchers with new biological insights and prompt additional questions regarding molecular and biophysical parameters that differentiate disease states but transcend MS measurements. Ion mobility spectrometry (IMS) is a gas-phase separation technique that directly complements MS measurements and expands understanding

regarding molecular shape and dynamics in biological systems. However, comparatively low sample utilization and separation efficiencies have hindered its broad adoption in the bioanalytical and clinical communities. With recent, broadly available technological advances in the field of printed circuit board (PCB) manufacturing a new

class of ion mobility separation is enabled that largely alleviates the drawbacks of its predecessors. The Structures for Lossless Ion Manipulations (SLIM) framework achieves this goal by establishing a dynamic electric field capable of confining ionized molecules for expanded periods of time along with a means to efficiently

fractionate the different classes prior to analysis using MS. Contemporary SLIM experiments achieve impressive levels of gas-phase ion separation, but focus only on one dimension of separation due to restrictions largely imposed by the underlying PCB electrode arrangements and control electronics. To cast the SLIM platform into

multiple separation dimensions and achieve new levels of biologically relevant diagnostics, the present effort aims to develop and disseminate an economical tandem IMS platform that integrates a series of innovative, simplifying strategies. These include the integration of a low-cost electrode switch that expands the experimental

versatility within the SLIM platform and a series of ion compression strategies aimed at creating high-density ion populations. Most importantly, and prior to MS analysis, we will exploit the highly compressed nature of the ion beams within the SLIM by subjecting these species to high intensity ultraviolet photons to induce molecular

disruption and yield more information regarding the target biological system. Concurrent efforts using laser irradiation and a new class of UV-C light emitting diodes will be compared with the latter offering considerable cost-savings. The third, composite goal of this project is to address the duty cycle issues of existing SLIM

concepts by fully multiplexing the tandem SLIM-ultraviolet photodissociation (UVPD) platform. With the added functionality of IMSn and the extended, multi-channel SLIM paths, the separation power of the system is anticipated to represent the state-of-the-art. At the conclusion of the proposed research we expect to realize a

fully functioning, high-efficiency SLIM-UVPD framework capable of interfacing to all mass analyzers classes and ready to address a suite of biological problems ranging from metabolomics to structural biology.