Implementation of simultaneous ultraviolet/visible and x-ray absorption spectroscopy with microfluidics
Category
Published on
Type
journal-article
Author
Olivia McCubbin Stepanic and Christopher J. Pollock and Kara A. Zielinski and William Foschi and Derek B. Rice and Lois Pollack and Serena DeBeer
Citation
McCubbin Stepanic, O., Pollock, C. J., Zielinski, K. A., Foschi, W., Rice, D. B., Pollack, L., & DeBeer, S. (2025). Implementation of simultaneous ultraviolet/visible and x-ray absorption spectroscopy with microfluidics. Review of Scientific Instruments, 96(1). https://doi.org/10.1063/5.0218572
Abstract
X-ray spectroscopies are uniquely poised to describe the geometric and electronic structure of metalloenzyme active sites under a wide variety of sample conditions. UV/Vis (ultraviolet/visible) spectroscopy is a similarly well-established technique that can identify and quantify catalytic intermediates. The work described here reports the first simultaneous collection of full in situ UV/Vis and high-energy resolution fluorescence detected x-ray absorption spectra. Implementation of a fiber optic UV/Vis spectrometer and parabolic mirror setup inside the dual array valence emission spectrometer allowing for simultaneous measurement of microfluidic flow and mixing samples at the Photon-In Photon-Out X-ray Spectroscopy beamline is described, and initial results on ferricyanide and a dilute iron protein are presented. In conjunction with advanced microfluidic mixing techniques, this will allow for the measurement and quantification of highly reactive catalytic intermediates at reaction-relevant temperatures on the millisecond timescale while avoiding potential complications induced by freeze quenching samples.
