Browsing by Author "Misiura, Anastasiia"

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    2D and 3D single-molecule microscopy to enhance protein chromatography
    (2022-08-02) Misiura, Anastasiia; Landes, Christy F.
    Over the last decade the pharmaceutical industry has been experiencing a scientific revolution, resulting in more biological-based therapeutics, also called biologics. Biologics are largely proteins or peptides, which have created a bottleneck in optimizing their purification processes. The major problem resides in the inability to predict and apply empirical processes to protein separation and purification. One ubiquitous method of protein purification and separation is chromatography. Despite its wide industrial usage and intensive development, there is still no detailed molecular-scale picture of protein dynamics during chromatographic separation. The lack of a predictive chromatographic theory is rooted in the absence of an in-depth understanding of interactions occurring inside a chromatographic column. To advance our understanding of underlying phenomena in a chromatographic column, 2D and 3D single-molecule techniques were utilized. We uncover the differences in protein motion in mobile phases, depending on salt concentration, and correlated the results to an ensemble chromatogram. We also demonstrate the importance of the combined influence of surface properties on adsorption-desorption kinetics of proteins to the stationary phase. Overall, we have shown that single-molecule methods can uncover the details of protein dynamics and transport at the nanoscale and relate them to ensemble chromatography and apply them to protein purification at-scale.
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    Mechanism for plasmon-generated solvated electrons
    (PNAS, 2023) Al-Zubeidi, Alexander; Ostovar, Behnaz; Carlin, Claire C.; Li, Boxi Cam; Lee, Stephen A.; Chiang, Wei-Yi; Gross, Niklas; Dutta, Sukanya; Misiura, Anastasiia; Searles, Emily K.; Chakraborty, Amrita; Roberts, Sean T.; Dionne, Jennifer A.; Rossky, Peter J.; Landes, Christy F.; Link, Stephan; Center for Adapting Flaws into Features
    Solvated electrons are powerful reducing agents capable of driving some of the most energetically expensive reduction reactions. Their generation under mild and sustainable conditions remains challenging though. Using near-ultraviolet irradiation under low-intensity one-photon conditions coupled with electrochemical and optical detection, we show that the yield of solvated electrons in water is increased more than 10 times for nanoparticle-decorated electrodes compared to smooth silver electrodes. Based on the simulations of electric fields and hot carrier distributions, we determine that hot electrons generated by plasmons are injected into water to form solvated electrons. Both yield enhancement and hot carrier production spectrally follow the plasmonic near-field. The ability to enhance solvated electron yields in a controlled manner by tailoring nanoparticle plasmons opens up a promising strategy for exploiting solvated electrons in chemical reactions.
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    Transforming Separation Science with Single-Molecule Methods
    (American Chemical Society, 2020) Calabrase, William; Bishop, Logan D.C.; Dutta, Chayan; Misiura, Anastasiia; Landes, Christy F.; Kisley, Lydia; Smalley-Curl Institute
    Empirical optimization of the multiscale parameters underlying chromatographic and membrane separations leads to enormous resource waste and production costs. A bottom-up approach to understand the physical phenomena underlying challenges in separations is possible with single-molecule observations of solute–stationary phase interactions. We outline single-molecule fluorescence techniques that can identify key interactions under ambient conditions. Next, we describe how studying increasingly complex samples heightens the relevance of single-molecule results to industrial applications. Finally, we illustrate how separation methods that have not been studied at the single-molecule scale can be advanced, using chiral chromatography as an example case. We hope new research directions based on a molecular approach to separations will emerge based on the ideas, technologies, and open scientific questions presented in this Perspective.