1
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Li M, Razumtcev A, Turner GA, Hwang Y, Simpson GJ. Fast Diffusion Characterization by Multiphoton Excited Fluorescence Recovery while Photobleaching. Anal Chem 2023; 95:14331-14340. [PMID: 37699550 DOI: 10.1021/acs.analchem.3c02638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Multiphoton-excited fluorescence recovery while photobleaching (FRWP) is demonstrated as a method for quantitative measurements of rapid molecular diffusion over microsecond to millisecond timescales. Diffusion measurements are crucial in assessing molecular mobility in cell biology, materials science, and pharmacology. Optical and fluorescence microscopy techniques enable non-invasive rapid analysis of molecular diffusion but can be challenging for systems with diffusion coefficients exceeding ∼100 μm2/s. As an example, fluorescence recovery after photobleaching (FRAP) operates on the implicit assumption of a comparatively fast photobleaching step prior to a relatively slow recovery and is not generally applicable for systems exhibiting substantial recovery during photobleaching. These challenges are exacerbated in multiphoton excitation by the lower excitation efficiency and competing effects from local heating. Herein, beam-scanning FRWP with patterned line-bleach illumination is introduced as a technique that addresses FRAP limitations and further extends its application range by measuring faster diffusion events. In FRWP, the recovery of fluorescence is continuously probed after each pass of a fast-scanning mirror, and the upper bound of measurable diffusion rates is, therefore, only limited by the mirror scanning frequency. A theoretical model describing transient fluctuations in fluorescence intensity arising as a result of combined contributions from photobleaching and localized photothermal effect is introduced along with a mathematical framework for quantifying fluorescence intensity temporal curves and recovering room-temperature diffusion coefficients. FRWP is then tested by characterization of normal diffusion of rhodamine-labeled bovine serum albumin, green fluorescence protein, and immunoglobulin G molecules in aqueous solutions of varying viscosity.
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Affiliation(s)
- Minghe Li
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Aleksandr Razumtcev
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Gwendylan A Turner
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Yechan Hwang
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Garth J Simpson
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
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2
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Ravindran R, Bacellar IOL, Castellanos-Girouard X, Wahba HM, Zhang Z, Omichinski JG, Kisley L, Michnick SW. Peroxisome biogenesis initiated by protein phase separation. Nature 2023; 617:608-615. [PMID: 37165185 PMCID: PMC10302873 DOI: 10.1038/s41586-023-06044-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 04/03/2023] [Indexed: 05/12/2023]
Abstract
Peroxisomes are organelles that carry out β-oxidation of fatty acids and amino acids. Both rare and prevalent diseases are caused by their dysfunction1. Among disease-causing variant genes are those required for protein transport into peroxisomes. The peroxisomal protein import machinery, which also shares similarities with chloroplasts2, is unique in transporting folded and large, up to 10 nm in diameter, protein complexes into peroxisomes3. Current models postulate a large pore formed by transmembrane proteins4; however, so far, no pore structure has been observed. In the budding yeast Saccharomyces cerevisiae, the minimum transport machinery includes the membrane proteins Pex13 and Pex14 and the cargo-protein-binding transport receptor, Pex5. Here we show that Pex13 undergoes liquid-liquid phase separation (LLPS) with Pex5-cargo. Intrinsically disordered regions in Pex13 and Pex5 resemble those found in nuclear pore complex proteins. Peroxisomal protein import depends on both the number and pattern of aromatic residues in these intrinsically disordered regions, consistent with their roles as 'stickers' in associative polymer models of LLPS5,6. Finally, imaging fluorescence cross-correlation spectroscopy shows that cargo import correlates with transient focusing of GFP-Pex13 and GFP-Pex14 on the peroxisome membrane. Pex13 and Pex14 form foci in distinct time frames, suggesting that they may form channels at different saturating concentrations of Pex5-cargo. Our findings lead us to suggest a model in which LLPS of Pex5-cargo with Pex13 and Pex14 results in transient protein transport channels7.
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Affiliation(s)
- Rini Ravindran
- Département de Biochimie, Université de Montréal, Montreal, Quebec, Canada
| | - Isabel O L Bacellar
- Département de Biochimie, Université de Montréal, Montreal, Quebec, Canada
- Douglas Research Centre, Montreal, Quebec, Canada
| | | | - Haytham M Wahba
- Département de Biochimie, Université de Montréal, Montreal, Quebec, Canada
- Department of Biochemistry, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Zhenghao Zhang
- Department of Physics, Case Western Reserve University, Cleveland, OH, USA
- Mitchell Physics Building (MPHY), College Station, TX, USA
| | - James G Omichinski
- Département de Biochimie, Université de Montréal, Montreal, Quebec, Canada
| | - Lydia Kisley
- Department of Physics, Case Western Reserve University, Cleveland, OH, USA
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, USA
| | - Stephen W Michnick
- Département de Biochimie, Université de Montréal, Montreal, Quebec, Canada.
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3
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Chen J. Simulating stochastic adsorption of diluted solute molecules at interfaces. AIP ADVANCES 2022; 12:015318. [PMID: 35070490 PMCID: PMC8758205 DOI: 10.1063/5.0064140] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
This report uses Monte Carlo simulations to connect stochastic single-molecule and ensemble surface adsorption of molecules from dilute solutions. Monte Carlo simulations often use a fundamental time resolution to simulate each discrete step for each molecule. The adsorption rate obtained from such a simulation surprisingly contains an error compared to the results obtained from the traditional method. Simulating adsorption kinetics is interesting in many processes, such as mass transportation within cells, the kinetics of drug-receptor interactions, membrane filtration, and other general reaction kinetics in diluted solutions. Thus, it is important to understand the origin of the disagreement and find a way to correct the results. This report reviews the traditional model, explains the single-molecule simulations, and introduces a method to correct the results of adsorption rate. For example, one can bin finer time steps into time steps of interest to simulate the fractal diffusion or simply introduce a correction factor for the simulations. Then two model systems, self-assembled monolayer (SAM) and biosensing on the patterned surface, are simulated to check the accuracy of the equations. It is found that the adsorption rate of SAM is highly dependent on the conditions and the uncertainty is large. However, the biosensing system is relatively accurate. This is because the concentration gradient near the interface varies significantly with reaction conditions for SAMs while relatively stable for the biosensing system.
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Affiliation(s)
- Jixin Chen
- Author to whom correspondence should be addressed:
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4
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Misiura A, Shen H, Tauzin L, Dutta C, Bishop LDC, Carrejo NC, Zepeda O J, Ramezani S, Moringo NA, Marciel AB, Rossky PJ, Landes CF. Single-Molecule Dynamics Reflect IgG Conformational Changes Associated with Ion-Exchange Chromatography. Anal Chem 2021; 93:11200-11207. [PMID: 34346671 DOI: 10.1021/acs.analchem.1c01799] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Conformational changes of antibodies and other biologics can decrease the effectiveness of pharmaceutical separations. Hence, a detailed mechanistic picture of antibody-stationary phase interactions that occur during ion-exchange chromatography (IEX) can provide critical insights. This work examines antibody conformational changes and how they perturb antibody motion and affect ensemble elution profiles. We combine IEX, three-dimensional single-protein tracking, and circular dichroism spectroscopy to investigate conformational changes of a model antibody, immunoglobulin G (IgG), as it interacts with the stationary phase as a function of salt conditions. The results indicate that the absence of salt enhances electrostatic attraction between IgG and the stationary phase, promotes surface-induced unfolding, slows IgG motion, and decreases elution from the column. Our results reveal previously unreported details of antibody structural changes and their influence on macroscale elution profiles.
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Affiliation(s)
- Anastasiia Misiura
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Hao Shen
- Department of Chemistry and Biochemistry, Kent State University, 800 E Summit Street, Kent, Ohio 44240, United States
| | - Lawrence Tauzin
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Chayan Dutta
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Logan D C Bishop
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Nicole C Carrejo
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Jorge Zepeda O
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Shahryar Ramezani
- Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Nicholas A Moringo
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Amanda B Marciel
- Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Peter J Rossky
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Christy F Landes
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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5
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Yoshida S, Kisley L. Super-resolution fluorescence imaging of extracellular environments. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 257:119767. [PMID: 33862370 DOI: 10.1016/j.saa.2021.119767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 06/12/2023]
Abstract
The extracellular matrix (ECM) is an important biophysical environment that plays a role in a number of physiological processes. The ECM is highly dynamic, with changes occurring as local, nanoscale, physicochemical variations in physical confinement and chemistry from the perspective of biological molecules. The length and time scale of ECM dynamics are challenging to measure with current spectroscopic techniques. Super-resolution fluorescence microscopy has the potential to probe local, nanoscale, physicochemical variations in the ECM. Here, we review super-resolution imaging and analysis methods and their application to study model nanoparticles and biomolecules within synthetic ECM hydrogels and the brain extracellular space (ECS). We provide a perspective of future directions for the field that can move super-resolution imaging of the ECM towards more biomedically-relevant samples. Overall, super-resolution imaging is a powerful tool that can increase our understanding of extracellular environments at new spatiotemporal scales to reveal ECM processes at the molecular-level.
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Affiliation(s)
- Shawn Yoshida
- Department of Physics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Lydia Kisley
- Department of Physics, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
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6
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Bishop LDC, Misiura A, Landes CF. A new metric for relating macroscopic chromatograms to microscopic surface dynamics: the distribution function ratio (DFR). Analyst 2021; 146:4268-4279. [PMID: 34105529 DOI: 10.1039/d1an00370d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heterogeneous stationary phase chemistry causes chromatographic tailing that lowers separation efficiency and complicates optimizing mobile phase conditions. Model-free metrics are attractive for assessing optimal separation conditions due to the low quantity of information required, but often do not reveal underlying mechanisms that cause tailing, for example, heterogeneous retention modes. We report a new metric, which we call the Distribution Function Ratio (DFR), based on a graphical comparison between the chromatogram and Gaussian cumulative distribution functions, achieving correspondence to ground truth surface dynamics with a single chromatogram. Using a Monte Carlo framework, we show that the DFR can predict the prevalence of heterogeneous retention modes with high precision when the relative desorption rate between modes is known, as in during surface dynamics experiments. Ground truth comparisons reveal that the DFR outperforms both the asymmetry factor and skewness by yielding a one-to-one correspondence with heterogeneous retention mode prevalence over a broad range of experimentally realistic values. Perhaps of more value, we illustrate that the DFR, when combined with the asymmetry factor and skewness, can estimate microscopic surface dynamics, providing valuable insights into surface chemistry using existing chromatographic instrumentation. Connecting ensemble results to microscopic quantities through the lens of simulation establishes a new chemistry-driven route to measuring and advancing separations.
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Affiliation(s)
- Logan D C Bishop
- Department of Chemistry, Rice University, Houston, Texas 77251, USA.
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7
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Yoshida S, Schmid W, Vo N, Calabrase W, Kisley L. Computationally-efficient spatiotemporal correlation analysis super-resolves anomalous diffusion. OPTICS EXPRESS 2021; 29:7616-7629. [PMID: 33726259 DOI: 10.1364/oe.416465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
Anomalous diffusion dynamics in confined nanoenvironments govern the macroscale properties and interactions of many biophysical and material systems. Currently, it is difficult to quantitatively link the nanoscale structure of porous media to anomalous diffusion within them. Fluorescence correlation spectroscopy super-resolution optical fluctuation imaging (fcsSOFI) has been shown to extract nanoscale structure and Brownian diffusion dynamics within gels, liquid crystals, and polymers, but has limitations which hinder its wider application to more diverse, biophysically-relevant datasets. Here, we parallelize the least-squares curve fitting step on a GPU improving computation times by up to a factor of 40, implement anomalous diffusion and two-component Brownian diffusion models, and make fcsSOFI more accessible by packaging it in a user-friendly GUI. We apply fcsSOFI to simulations of the protein fibrinogen diffusing in polyacrylamide of varying matrix densities and super-resolve locations where slower, anomalous diffusion occurs within smaller, confined pores. The improvements to fcsSOFI in speed, scope, and usability will allow for the wider adoption of super-resolution correlation analysis to diverse research topics.
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8
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Bishop LD, Misiura A, Moringo NA, Landes CF. Unraveling peak asymmetry in chromatography through stochastic theory powered Monte Carlo simulations. J Chromatogr A 2020; 1625:461323. [DOI: 10.1016/j.chroma.2020.461323] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 12/29/2022]
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9
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Shayegan M, Tahvildari R, Metera K, Kisley L, Michnick SW, Leslie SR. Probing Inhomogeneous Diffusion in the Microenvironments of Phase-Separated Polymers under Confinement. J Am Chem Soc 2019; 141:7751-7757. [DOI: 10.1021/jacs.8b13349] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Marjan Shayegan
- Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada
| | - Radin Tahvildari
- Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada
| | - Kimberly Metera
- Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada
| | - Lydia Kisley
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Stephen W. Michnick
- Département de Biochimie, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Sabrina R. Leslie
- Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada
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10
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Thompson S, Pappas D. A fluorescence toolbox: A review of investigation of electrophoretic separations, process, and interfaces. Electrophoresis 2018; 40:606-615. [DOI: 10.1002/elps.201800310] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/06/2018] [Accepted: 09/06/2018] [Indexed: 01/23/2023]
Affiliation(s)
- S. Thompson
- Department of Chemistry and Biochemistry; Texas Tech University; Lubbock TX USA
| | - Dimitri Pappas
- Department of Chemistry and Biochemistry; Texas Tech University; Lubbock TX USA
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11
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Inagawa A, Okada Y, Okada T. Electrophoresis in ice surface grooves for probing protein affinity to a specific plane of ice crystal. Talanta 2018; 183:345-351. [DOI: 10.1016/j.talanta.2017.12.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 12/20/2017] [Accepted: 12/21/2017] [Indexed: 01/26/2023]
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12
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Zhang P, Maldonis JJ, Liu Z, Schroers J, Voyles PM. Spatially heterogeneous dynamics in a metallic glass forming liquid imaged by electron correlation microscopy. Nat Commun 2018; 9:1129. [PMID: 29555920 PMCID: PMC5859095 DOI: 10.1038/s41467-018-03604-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/25/2018] [Indexed: 11/08/2022] Open
Abstract
Supercooled liquids exhibit spatial heterogeneity in the dynamics of their fluctuating atomic arrangements. The length and time scales of the heterogeneous dynamics are central to the glass transition and influence nucleation and growth of crystals from the liquid. Here, we report direct experimental visualization of the spatially heterogeneous dynamics as a function of temperature in the supercooled liquid state of a Pt-based metallic glass, using electron correlation microscopy with sub-nanometer resolution. An experimental four-point space-time correlation function demonstrates a growing dynamic correlation length, ξ, upon cooling of the liquid toward the glass transition temperature. ξ as a function of the relaxation time τ are in good agreement with Adam-Gibbs theory, inhomogeneous mode-coupling theory and random first-order transition theory of the glass transition. The same experiments demonstrate the existence of a nanometer thickness near-surface layer with order of magnitude shorter relaxation time than inside the bulk.
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Affiliation(s)
- Pei Zhang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jason J Maldonis
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ze Liu
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
| | - Jan Schroers
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, 06511, USA
| | - Paul M Voyles
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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13
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Shen H, Tauzin LJ, Baiyasi R, Wang W, Moringo N, Shuang B, Landes CF. Single Particle Tracking: From Theory to Biophysical Applications. Chem Rev 2017; 117:7331-7376. [PMID: 28520419 DOI: 10.1021/acs.chemrev.6b00815] [Citation(s) in RCA: 273] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
After three decades of developments, single particle tracking (SPT) has become a powerful tool to interrogate dynamics in a range of materials including live cells and novel catalytic supports because of its ability to reveal dynamics in the structure-function relationships underlying the heterogeneous nature of such systems. In this review, we summarize the algorithms behind, and practical applications of, SPT. We first cover the theoretical background including particle identification, localization, and trajectory reconstruction. General instrumentation and recent developments to achieve two- and three-dimensional subdiffraction localization and SPT are discussed. We then highlight some applications of SPT to study various biological and synthetic materials systems. Finally, we provide our perspective regarding several directions for future advancements in the theory and application of SPT.
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Affiliation(s)
- Hao Shen
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Lawrence J Tauzin
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Rashad Baiyasi
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Wenxiao Wang
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Nicholas Moringo
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Bo Shuang
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Christy F Landes
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
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14
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Bryce DA, Kitt JP, Harris JM. Confocal Raman Microscopy Investigation of Molecular Transport into Individual Chromatographic Silica Particles. Anal Chem 2017; 89:2755-2763. [PMID: 28192968 DOI: 10.1021/acs.analchem.6b03498] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Porous silica is used as a support in a variety of separation processes, including chromatographic separation and solid-phase extraction. The resolution and efficiency of these applications is significantly impacted by the kinetics of partitioning and molecular transport into the interior of the porous particles. Molecular transport in porous silica has been explored previously by measuring chromatographic elution profiles, but such measurements are limited to relatively low retention conditions, where within-particle molecular transport must be inferred from elution profiles of solutes emerging from a packed column. In this work, a measurement of within-particle molecular transport is carried out using confocal Raman microscopy to probe the time-dependent accumulation of pyrene from an aqueous mobile phase into the center of individual C18-chromatographic particles. The measured time constants for pyrene accumulation were much slower than diffusion-limited transport of solute in solution to the particle surface. Furthermore, the accumulation into the center of the particle did not show a time-lag characteristic of slow-transport into the particle interior. The exponential rise of pyrene concentration is, however, consistent with first-order Langmuir adsorption kinetics at low surface coverages. The linear dependence of the time-constant on particle radius indicates an adsorption barrier near the outer boundary of the particle, where the accumulation rate depends on flux across the boundary (proportional to the particle area) to satisfy the within-particle capacity at equilibrium (proportional to the particle volume). The pyrene accumulation kinetics into the porous particle, expressed as a heterogeneous rate constant, were nearly 50-times faster than the pyrene adsorption rate at a planar C18-functionalized silica surface, which demonstrates the impact of multiple surface encounters within the porous structure leading to much greater capture efficiency compared to a planar surface. Monte Carlo simulations of within-particle pyrene diffusion, with the adsorption efficiency estimated from the planar-surface adsorption rate, predict a diffusion-to-capture distance within the porous particle that is within 40% of that observed in the radial dependence of the pyrene within-particle accumulation results.
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Affiliation(s)
- David A Bryce
- Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - Jay P Kitt
- Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - Joel M Harris
- Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
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15
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Lupo KM, Hinton DA, Ng JD, Padilla NA, Goldsmith RH. Probing Heterogeneity and Bonding at Silica Surfaces through Single-Molecule Investigation of Base-Mediated Linkage Failure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:9171-9179. [PMID: 27541852 DOI: 10.1021/acs.langmuir.6b02456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The nature of silica surfaces is relevant to many chemical systems, including heterogeneous catalysis and chromatographies utilizing functionalized-silica stationary phases. Surface linkages must be robust to achieve wide and reliable applicability. However, silyl ether-silica support linkages are known to be susceptible to detachment when exposed to basic conditions. We use single-molecule spectroscopy to examine the rate of surface linkage failure upon exposure to base at a variety of deposition conditions. Kinetic analysis elucidates the role of thermal annealing and addition of blocking layers in increasing stability. Critically, it was found that successful surface modification strategies alter the rate at which base molecules approach the silica surface as opposed to reducing surface linkage reactivity. Our results also demonstrate that the innate structural diversity of the silica surface is likely the cause of observed heterogeneity in surface-linkage disruption kinetics.
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Affiliation(s)
- Katherine M Lupo
- Department of Chemistry, The University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Daniel A Hinton
- Department of Chemistry, The University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - James D Ng
- Department of Chemistry, The University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Nicolas A Padilla
- Department of Chemistry, The University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Randall H Goldsmith
- Department of Chemistry, The University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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16
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Bailey KA, Schultz ZD. Tracking Bulk and Interfacial Diffusion Using Multiplex Coherent Anti-Stokes Raman Scattering Correlation Spectroscopy. J Phys Chem B 2016; 120:6819-28. [PMID: 27322504 PMCID: PMC4962611 DOI: 10.1021/acs.jpcb.6b04304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Multiplex coherent anti-Stokes Raman scattering correlation spectroscopy (CARS-CS) is shown as a label-free, chemically specific approach for monitoring the molecular mobility of particles in solution and at interfaces on the millisecond time scale. The CARS spectral range afforded by broadband excitation facilitates a quantitative measurement for the number of particles in the focal volume, whereas the autocorrelation of spectral data elucidates dynamic events, such as diffusion. The measured diffusion coefficients for polymer beads ranging from 100 nm to 1.1 μm in diameter are on the order of 10(-8)-10(-9) cm(2)/s, in good agreement with predicted Stokes-Einstein values. Diffusion at different interfaces shows particles are fastest in bulk medium, marginally slower at the liquid/glass interface, and 1.5-2 times slower rate at the air/liquid interface. Multivariate curve resolution analysis of distinct spectral features in multiplex CARS measurement distinguishes different composition lipid vesicles in a mixture diffusing through the focal volume. The observed diffusion is consistent with results obtained from single particle tracking experiments. This work demonstrates the utility of multiplex CARS correlation spectroscopy for monitoring particle diffusion from different chemical species across diverse interfaces.
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Affiliation(s)
- Karen A. Bailey
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Zachary D. Schultz
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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17
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Täuber D, Radscheit K, von Borczyskowski C, Schulz M, Osipov VA. Fluorescence correlation spectroscopy in thin films at reflecting substrates as a means to study nanoscale structure and dynamics at soft-matter interfaces. Phys Rev E 2016; 94:012804. [PMID: 27575199 DOI: 10.1103/physreve.94.012804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Indexed: 05/03/2023]
Abstract
Structure and dynamics at soft-matter interfaces play an important role in nature and technical applications. Optical single-molecule investigations are noninvasive and capable to reveal heterogeneities at the nanoscale. In this work we develop an autocorrelation function (ACF) approach to retrieve tracer diffusion parameters obtained from fluorescence correlation spectroscopy (FCS) experiments in thin liquid films at reflecting substrates. This approach then is used to investigate structure and dynamics in 100-nm-thick 8CB liquid crystal films on silicon wafers with five different oxide thicknesses. We find a different extension of the structural reorientation of 8CB at the solid-liquid interface for thin and for thick oxide. For the thin oxides, the perylenediimide tracer diffusion dynamics in general agrees with the hydrodynamic modeling using no-slip boundary conditions with only a small deviation close to the substrate, while a considerably stronger decrease of the interfacial tracer diffusion is found for the thick oxides.
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Affiliation(s)
- Daniela Täuber
- Institute of Physics, Technische Universität Chemnitz, D-09107 Chemnitz, Germany
| | - Kathrin Radscheit
- Institute of Physics, Technische Universität Chemnitz, D-09107 Chemnitz, Germany
| | | | - Michael Schulz
- Institute of Physics, Technische Universität Chemnitz, D-09107 Chemnitz, Germany
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18
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Wang D, Chin HY, He C, Stoykovich MP, Schwartz DK. Polymer Surface Transport Is a Combination of in-Plane Diffusion and Desorption-Mediated Flights. ACS Macro Lett 2016; 5:509-514. [PMID: 35607234 DOI: 10.1021/acsmacrolett.6b00183] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous studies of polymer motion at solid/liquid interfaces described the transport in the context of a continuous time random walk (CTRW) process, in which diffusion switches between desorption-mediated "flights" (i.e., hopping) and surface-adsorbed waiting-time intervals. However, it has been unclear whether the waiting times represented periods of complete immobility or times during which molecules engaged in a different (e.g., slower or confined) mode of interfacial transport. Here we designed high-throughput, single-molecule tracking measurements to address this question. Specifically, we studied polymer dynamics on either chemically homogeneous or nanopatterned surfaces (hexagonal diblock copolymer films) with chemically distinct domains, where polymers were essentially excluded from the low-affinity domains, eliminating the possibility of significant continuous diffusion in the absence of desorption-mediated flights. Indeed, the step-size distributions on homogeneous surfaces exhibited an additional diffusive mode that was missing on the chemically heterogeneous nanopatterned surfaces, confirming the presence of a slow continuous mode due to 2D in-plane diffusion. Kinetic Monte Carlo simulations were performed to test this model and, with the theoretical in-plane diffusion coefficient of D2D = 0.20 μm2/s, we found a good agreement between simulations and experimental data on both chemically homogeneous and nanopatterned surfaces.
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Affiliation(s)
- Dapeng Wang
- Department of Chemical and
Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Huai-Ying Chin
- Department of Chemical and
Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Chunlin He
- Department of Chemical and
Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Mark P. Stoykovich
- Department of Chemical and
Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Daniel K. Schwartz
- Department of Chemical and
Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
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19
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Cooper JT, Harris JM. Spatially Multiplexed Imaging: Fluorescence Correlation Spectroscopy for Efficient Measurement of Molecular Diffusion at Solid-Liquid Interfaces. APPLIED SPECTROSCOPY 2016; 70:695-701. [PMID: 26887989 DOI: 10.1177/0003702816631312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/02/2015] [Indexed: 06/05/2023]
Abstract
Fluorescence correlation spectroscopy (FCS) has become an important technique for the characterization of molecular dynamics, especially at interfaces. Fluorescence correlation spectroscopy provides both temporal and spatial resolution for measuring fast processes at equilibrium through analysis of noise in fluorescence intensities from the statistical fluctuations in a small number of molecules. The small molecular populations produce very low-level fluorescence signals, where time-averaging the fluorescence autocorrelation function is needed to generate reasonable signal-to-noise (S/N) ratios. Recently imaging cameras have been adapted to FCS measurements of molecular dynamics at interfaces (membranes and surfaces) through the use of electron-multiplying charge-coupled device (EM-CCD) detectors for acquisition of fluorescence from addressable areas on the detector. This approach provides a major advantage over traditional focused-spot FCS by allowing electronic control over the location and area of the acquired region on the sample surface. Imaging-FCS can also provide a spatial multiplexing advantage through its ability to measure intensity data from larger areas in parallel with no loss of time resolution. In this work, this multiplexing advantage is exploited to determine molecular diffusion rates from the simultaneous measurement of multiple areas on a surface, the autocorrelation traces from which are averaged to improve the S/N ratio. As proof of concept, the diffusion of 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI) on a C18-modified interface was measured using this multiplexed method and compared to autocorrelation data acquired from a single spot. Due to the slow thermal recovery of the EM-CCD that inhibits fast time-averaging, spatial multiplexing in imaging-FCS provides an eightyfold time savings to reach the same S/N ratio as multiple (time-averaged) measurements from a single spot.
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Affiliation(s)
- Justin T Cooper
- Department of Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Joel M Harris
- Department of Chemistry, University of Utah, Salt Lake City, Utah, USA
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20
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Tauzin LJ, Shen H, Moringo NA, Roddy MH, Bothof CA, Griesgraber GW, McNulty AK, Rasmussen JK, Landes CF. Variable surface transport modalities on functionalized nylon films revealed with single molecule spectroscopy. RSC Adv 2016. [DOI: 10.1039/c5ra25592a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Functionalization of separation membranes with ion-exchange ligands allows control of the surface mobility of protein molecules facilitating optimized membrane design.
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Affiliation(s)
| | - Hao Shen
- Department of Chemistry
- Rice University
- Houston
- USA
| | | | | | - Cathy A. Bothof
- 3M Corporate Research Laboratories
- 3M Center 201-3E-03
- St. Paul
- USA
| | | | - Amy K. McNulty
- 3M Corporate Research Laboratories
- 3M Center 201-3E-03
- St. Paul
- USA
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21
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Kisley L, Brunetti R, Tauzin LJ, Shuang B, Yi X, Kirkeminde AW, Higgins DA, Weiss S, Landes CF. Characterization of Porous Materials by Fluorescence Correlation Spectroscopy Super-resolution Optical Fluctuation Imaging. ACS NANO 2015; 9:9158-66. [PMID: 26235127 PMCID: PMC10706734 DOI: 10.1021/acsnano.5b03430] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Porous materials such as cellular cytosol, hydrogels, and block copolymers have nanoscale features that determine macroscale properties. Characterizing the structure of nanopores is difficult with current techniques due to imaging, sample preparation, and computational challenges. We produce a super-resolution optical image that simultaneously characterizes the nanometer dimensions of and diffusion dynamics within porous structures by correlating stochastic fluctuations from diffusing fluorescent probes in the pores of the sample, dubbed here as "fluorescence correlation spectroscopy super-resolution optical fluctuation imaging" or "fcsSOFI". Simulations demonstrate that structural features and diffusion properties can be accurately obtained at sub-diffraction-limited resolution. We apply our technique to image agarose hydrogels and aqueous lyotropic liquid crystal gels. The heterogeneous pore resolution is improved by up to a factor of 2, and diffusion coefficients are accurately obtained through our method compared to diffraction-limited fluorescence imaging and single-particle tracking. Moreover, fcsSOFI allows for rapid and high-throughput characterization of porous materials. fcsSOFI could be applied to soft porous environments such hydrogels, polymers, and membranes in addition to hard materials such as zeolites and mesoporous silica.
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Affiliation(s)
- Lydia Kisley
- Department of Chemistry and Rice University, Houston, Texas 77251, United States
| | - Rachel Brunetti
- Department of Physics, Scripps College, Claremont, California 91711, United States
| | - Lawrence J. Tauzin
- Department of Chemistry and Rice University, Houston, Texas 77251, United States
| | - Bo Shuang
- Department of Chemistry and Rice University, Houston, Texas 77251, United States
| | - Xiyu Yi
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Alec W. Kirkeminde
- Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
| | - Daniel A. Higgins
- Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
| | - Shimon Weiss
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
- Department of Physiology, and University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Christy F. Landes
- Department of Chemistry and Rice University, Houston, Texas 77251, United States
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77251, United States
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22
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Wang D, Hu R, Mabry JN, Miao B, Wu DT, Koynov K, Schwartz DK. Scaling of Polymer Dynamics at an Oil–Water Interface in Regimes Dominated by Viscous Drag and Desorption-Mediated Flights. J Am Chem Soc 2015; 137:12312-20. [DOI: 10.1021/jacs.5b07108] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dapeng Wang
- Department
of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Renfeng Hu
- Department
of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Joshua N. Mabry
- Department
of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Bing Miao
- College
of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - David T. Wu
- Department
of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Kaloian Koynov
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Daniel K. Schwartz
- Department
of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
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23
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Mabry JN, Schwartz DK. Tuning the Flight Length of Molecules Diffusing on a Hydrophobic Surface. J Phys Chem Lett 2015; 6:2065-2069. [PMID: 26266503 DOI: 10.1021/acs.jpclett.5b00799] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Transport at solid-liquid interfaces is critical to self-assembly, biosensing, and heterogeneous catalysis, but surface diffusion remains difficult to characterize and rationally manipulate, due to the inherent heterogeneity of adsorption on solid surfaces. Using single-molecule tracking, we characterized the diffusion of a fluorescent long-chain surfactant on a hydrophobic surface, which involved periods of confinement alternating with bulk-mediated "flights". The concentration of methanol in solution was varied to tune the strength of the hydrophobic surface-molecule interaction. The frequency of confinement had a nonmonotonic dependence on methanol concentration that reflected the relative influence of anomalously strong adsorption sites. By carefully accounting for the effect of this surface heterogeneity, we demonstrated that flight lengths increased monotonically as the hydrophobic attraction decreased, in agreement with theoretical predictions for bulk-mediated surface diffusion. The theory provided an accurate description of surface diffusion, despite the system being heterogeneous, and can be leveraged to optimize molecular search and assembly processes.
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Affiliation(s)
- Joshua N Mabry
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
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24
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Tran-Ba KH, Higgins DA, Ito T. Fluorescence Recovery after Photobleaching and Single-Molecule Tracking Measurements of Anisotropic Diffusion within Identical Regions of a Cylinder-Forming Diblock Copolymer Film. Anal Chem 2015; 87:5802-9. [PMID: 25923826 DOI: 10.1021/acs.analchem.5b01041] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This work demonstrates ensemble and single-molecule diffusion measurements within identical regions of a cylinder-forming polystyrene-poly(ethylene oxide) diblock copolymer (PS-b-PEO) film using fluorescence recovery after photobleaching (FRAP) and single-molecule tracking (SMT). A PS-b-PEO film (∼4 μm thick) with aligned cylindrical PEO microdomains containing 10 μM sulforhodamine B (SRB) was prepared by directional solvent-vapor penetration (SVP) of 1,4-dioxane. The ensemble diffusion behavior of SRB in the microdomains was assessed in FRAP studies of circular photobleached regions (∼7 μm in diameter). The SRB concentration was subsequently reduced by additional photobleaching, and the diffusion of individual SRB molecules was explored using SMT in the identical area (∼16 × 16 μm(2)). The FRAP data showed anisotropic fluorescence recovery, yielding the average microdomain orientation. The extent of fluorescence recovery observed (∼90%) demonstrated long-range microdomain connectivity, while the recovery time dependence provided an ensemble measurement of the SRB diffusion coefficient within the cylindrical microdomains. The SMT data exhibited one-dimensional diffusion of individual SRB molecules along the SVP direction across the entire film thickness, as consistent with the FRAP results. Importantly, the average of the single-molecule diffusion coefficients was close to the value obtained from FRAP in the identical area. In some cases, SMT offered smaller diffusion coefficients than FRAP, possibly due to contributions from SRB molecules confined within short PEO microdomains. The implementation of FRAP and SMT measurements in identical areas provides complementary information on molecular diffusion with minimal influence of sample heterogeneity, permitting direct comparison of ensemble and single-molecule diffusion behavior.
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Affiliation(s)
- Khanh-Hoa Tran-Ba
- Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
| | - Daniel A Higgins
- Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
| | - Takashi Ito
- Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
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25
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Affiliation(s)
- Lydia Kisley
- Department of Chemistry and Department of Electrical and Computer
Engineering,
Rice Quantum Institute, Rice University, 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department of Chemistry and Department of Electrical and Computer
Engineering,
Rice Quantum Institute, Rice University, 6100 Main Street, MS-60, Houston, Texas 77005, United States
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26
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Cooper J, Harris JM. Fluorescence-Correlation Spectroscopy Study of Molecular Transport within Reversed-Phase Chromatographic Particles Compared to Planar Model Surfaces. Anal Chem 2014; 86:11766-72. [DOI: 10.1021/ac503250a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Justin Cooper
- Department of Chemistry, University of Utah, 315 South 1400
East, Salt Lake City, Utah 84112-0805, United States
| | - Joel M. Harris
- Department of Chemistry, University of Utah, 315 South 1400
East, Salt Lake City, Utah 84112-0805, United States
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