Desorption/Ionization in Nanofiber SALDI Mass Spectrometry

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Drs. Susan Olesik and Zachary Schultz and their groups at Ohio State University are working to improve on Surface-Assisted Laser Desorption Ionization (SALDI) mass spectrometry, a powerful analytical method for the detection of both small chemical species and large macromolecules (e.g.- polymers and proteins).

Insights gained in this work should enable enhanced environmental analyses, such as monitoring trace-level amounts of pollutants in natural waters and human disease detection through tracking disease-related species in biological fluids at increasingly low levels. To enhance the opportunities for historically underrepresented students in science, such as first generation college students and racial minorities, recruitment efforts by both research groups will allow these undergraduates to work alongside graduate students in the respective laboratories to acquire skills in state-of-the art laboratory science.

The Olesik and Schultz group are working to improve the performance of nanofiber-based surface assisted laser desorption/ ionization, SALDI, through fundamental studies of energy transfer between the excitation laser and the SALDI substrate, within the substrate, and from the substrate to the analyte molecules. The overarching goal of this work is to markedly enhance the performance of nanofiber-based , SALDI.

Often SALDI provides significant advantages for analysis of small molecules compared to matrix-assisted laser desorption ionization, MALDI, due to the low detection limits, improved reproducibility of signal/noise in the mass spectrum, and the absence of a “chemical” background in the low mass range arising from ionization of the matrix. Nanofiber-based SALDI has all the advantages of other implementations; however, it can also often achieve strong signal/noise for specific high molecular weight compounds.

The performance of nanofiber based SALDI will be improved through fundamental studies of energy transfer between the excitation laser and SALDI substrate, within the substrate, and from the substrate to the analyte molecules. This mechanistic study of how energy transfer impacts desorption/ionization for nanofiber-based SALDI is expected to define high performing constructs appropriate for trace detection of both low and high molecular weight analytes.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.