1
|
Ajith VJ, Patil S. Translational Diffusion of a Fluorescent Tracer Molecule in Nanoconfined Water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:1034-1044. [PMID: 35007074 DOI: 10.1021/acs.langmuir.1c02550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Diffusion of tracer dye molecules in water confined to the nanoscale is an important subject with a direct bearing on many technological applications. It is not yet clear, however, if the dynamics of water in hydrophilic as well as hydrophobic nanochannels remains bulk-like. Here, we present diffusion measurement of a fluorescent dye molecule in water confined to the nanoscale between two hydrophilic surfaces whose separation can be controlled with a precision of less than a nm. We observe that the fluorescence intensities correlate over fast (∼30 μs) and slow (∼1000 μs) time components. The slow time scale is due to adsorption of fluorophores to the confining walls, and it disappears in the presence of 1 M salt. The fast component is attributed to diffusion of dye molecules in the gap. It is found to be bulk-like for sub-10 nm separations and indicates that the viscosity of water under confinement remains unaltered up to a confinement gap as small as ∼5 nm. Our findings contradict some of the recent measurements of diffusion under nanoconfinement; however, they are consistent with many estimates of self-diffusion using molecular dynamics simulations and measurements using neutron scattering experiments.
Collapse
Affiliation(s)
- V J Ajith
- Department of Physics, Indian Institute of Science Education and Research Pune, Pune 411008, Maharashtra, India
| | - Shivprasad Patil
- Department of Physics, Indian Institute of Science Education and Research Pune, Pune 411008, Maharashtra, India
| |
Collapse
|
2
|
Gravelle S, Ybert C. Flow-induced shift of the Donnan equilibrium for ultra-sensitive mass transport measurement through a single nanochannel. J Chem Phys 2019; 151:244503. [DOI: 10.1063/1.5133888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Simon Gravelle
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
- School of Engineering and Material Science, Queen Mary University of London, London, United Kingdom
| | - Christophe Ybert
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| |
Collapse
|
3
|
Kumarasinghe R, Ito T, Higgins DA. Nanoconfinement and Mass Transport in Silica Mesopores: the Role of Charge at the Single Molecule and Single Pore Levels. Anal Chem 2019; 92:1416-1423. [DOI: 10.1021/acs.analchem.9b04589] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ruwandi Kumarasinghe
- 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
| | - Daniel A. Higgins
- Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
| |
Collapse
|
4
|
Shen H, Tauzin LJ, Wang W, Hoener B, Shuang B, Kisley L, Hoggard A, Landes CF. Single-Molecule Kinetics of Protein Adsorption on Thin Nylon-6,6 Films. Anal Chem 2016; 88:9926-9933. [DOI: 10.1021/acs.analchem.5b04081] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Hao Shen
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Lawrence J. Tauzin
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Wenxiao Wang
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Benjamin Hoener
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Bo Shuang
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Lydia Kisley
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Anneli Hoggard
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Christy F. Landes
- Department of Chemistry, ‡Department of Electrical
and Computer Engineering, and §Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| |
Collapse
|
5
|
Wei L, Ye Z, Luo W, Chen B, Xiao L. Redistribution of fluorescent molecules at the solid/liquid interface with total internal reflection illumination. Talanta 2016; 155:229-34. [PMID: 27216678 DOI: 10.1016/j.talanta.2016.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 04/06/2016] [Accepted: 04/09/2016] [Indexed: 10/21/2022]
Abstract
Many intriguing physical and chemical processes commonly take place at the solid/liquid interface. Total internal reflection illumination, together with single molecule spectroscopy, provides a robust platform for the selective exploration of kinetic processes close the interface. With these techniques, it was observed that the distribution of Rhodamine B molecules close to a solid/liquid interface could be regulated in a photo-induced route. The laser-induced repulsion force at this interface is enough to compromise the Brownian diffusion of single molecules in a range of several hundred nanometers normal to the solid/liquid interface. This observation is fundamentally and practically interesting because moderate laser intensity is enough to initiate this repulsion effect. Therefore, it might display extensive applications in the development of photo-modulation technique with high throughput capability.
Collapse
Affiliation(s)
- Lin Wei
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Zhongju Ye
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Wenjuan Luo
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Bo Chen
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Lehui Xiao
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China.
| |
Collapse
|
6
|
Kisley L, Poongavanam MV, Kourentzi K, Willson RC, Landes CF. pH-dependence of single-protein adsorption and diffusion at a liquid chromatographic interface. J Sep Sci 2015; 39:682-8. [DOI: 10.1002/jssc.201500809] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/04/2015] [Accepted: 09/05/2015] [Indexed: 12/22/2022]
Affiliation(s)
- Lydia Kisley
- Department of Chemistry; Rice University; Houston TX USA
| | | | - Katerina Kourentzi
- Department of Chemical & Biomolecular Engineering; University of Houston; Houston TX USA
| | - Richard C. Willson
- Department of Biology & Biochemistry; University of Houston; Houston TX USA
- Department of Chemical & Biomolecular Engineering; University of Houston; Houston TX USA
- Houston Methodist Research Institute; Houston TX USA
- Centro de Biotecnología FEMSA, Departamento de Biotecnología e Ingeniería de Alimentos; Tecnológico de Monterrey; Monterrey NL Mexico
| | - Christy F. Landes
- Department of Chemistry; Rice University; Houston TX USA
- Department of Electrical and Computer Engineering; Rice University; Houston TX USA
| |
Collapse
|
7
|
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
| |
Collapse
|
8
|
Hutchison JA, Uji-i H, Deres A, Vosch T, Rocha S, Müller S, Bastian AA, Enderlein J, Nourouzi H, Li C, Herrmann A, Müllen K, De Schryver F, Hofkens J. A surface-bound molecule that undergoes optically biased Brownian rotation. NATURE NANOTECHNOLOGY 2014; 9:131-6. [PMID: 24441983 DOI: 10.1038/nnano.2013.285] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 11/25/2013] [Indexed: 05/09/2023]
Abstract
Developing molecular systems with functions analogous to those of macroscopic machine components, such as rotors, gyroscopes and valves, is a long-standing goal of nanotechnology. However, macroscopic analogies go only so far in predicting function in nanoscale environments, where friction dominates over inertia. In some instances, ratchet mechanisms have been used to bias the ever-present random, thermally driven (Brownian) motion and drive molecular diffusion in desired directions. Here, we visualize the motions of surface-bound molecular rotors using defocused fluorescence imaging, and observe the transition from hindered to free Brownian rotation by tuning medium viscosity. We show that the otherwise random rotations can be biased by the polarization of the excitation light field, even though the associated optical torque is insufficient to overcome thermal fluctuations. The biased rotation is attributed instead to a fluctuating-friction mechanism in which photoexcitation of the rotor strongly inhibits its diffusion rate.
Collapse
Affiliation(s)
- James A Hutchison
- 1] Laboratory for Photochemistry and Spectroscopy, Katholieke Universiteit Leuven, Heverlee 3001 Belgium [2] ISIS & icFRC, Université de Strasbourg & CNRS UMR 7006, Strasbourg 67000, France
| | - Hiroshi Uji-i
- Laboratory for Photochemistry and Spectroscopy, Katholieke Universiteit Leuven, Heverlee 3001 Belgium
| | - Ania Deres
- Laboratory for Photochemistry and Spectroscopy, Katholieke Universiteit Leuven, Heverlee 3001 Belgium
| | - Tom Vosch
- Nano-Science Center/Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Susana Rocha
- Laboratory for Photochemistry and Spectroscopy, Katholieke Universiteit Leuven, Heverlee 3001 Belgium
| | - Sibylle Müller
- Synthetic Chemistry Group, Max Plank Institute for Polymer Research, Mainz D-55128 Germany
| | - Andreas A Bastian
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, Groningen 9747 AG, The Netherlands
| | - Jörg Enderlein
- Drittes Physikalisches Institut, Universität Göttingen, Göttingen D-37077 Germany
| | - Hassan Nourouzi
- Synthetic Chemistry Group, Max Plank Institute for Polymer Research, Mainz D-55128 Germany
| | - Chen Li
- Synthetic Chemistry Group, Max Plank Institute for Polymer Research, Mainz D-55128 Germany
| | - Andreas Herrmann
- Department of Polymer Chemistry, Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, Groningen 9747 AG, The Netherlands
| | - Klaus Müllen
- Synthetic Chemistry Group, Max Plank Institute for Polymer Research, Mainz D-55128 Germany
| | - Frans De Schryver
- Laboratory for Photochemistry and Spectroscopy, Katholieke Universiteit Leuven, Heverlee 3001 Belgium
| | - Johan Hofkens
- 1] Laboratory for Photochemistry and Spectroscopy, Katholieke Universiteit Leuven, Heverlee 3001 Belgium [2] Nano-Science Center/Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| |
Collapse
|
9
|
Unified superresolution experiments and stochastic theory provide mechanistic insight into protein ion-exchange adsorptive separations. Proc Natl Acad Sci U S A 2014; 111:2075-80. [PMID: 24459184 DOI: 10.1073/pnas.1318405111] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Chromatographic protein separations, immunoassays, and biosensing all typically involve the adsorption of proteins to surfaces decorated with charged, hydrophobic, or affinity ligands. Despite increasingly widespread use throughout the pharmaceutical industry, mechanistic detail about the interactions of proteins with individual chromatographic adsorbent sites is available only via inference from ensemble measurements such as binding isotherms, calorimetry, and chromatography. In this work, we present the direct superresolution mapping and kinetic characterization of functional sites on ion-exchange ligands based on agarose, a support matrix routinely used in protein chromatography. By quantifying the interactions of single proteins with individual charged ligands, we demonstrate that clusters of charges are necessary to create detectable adsorption sites and that even chemically identical ligands create adsorption sites of varying kinetic properties that depend on steric availability at the interface. Additionally, we relate experimental results to the stochastic theory of chromatography. Simulated elution profiles calculated from the molecular-scale data suggest that, if it were possible to engineer uniform optimal interactions into ion-exchange systems, separation efficiencies could be improved by as much as a factor of five by deliberately exploiting clustered interactions that currently dominate the ion-exchange process only accidentally.
Collapse
|
10
|
|
11
|
Daniels CR, Tauzin LJ, Foster E, Advincula RC, Landes CF. On the pH-responsive, charge-selective, polymer-brush-mediated transport probed by traditional and scanning fluorescence correlation spectroscopy. J Phys Chem B 2013; 117:4284-90. [PMID: 23092304 PMCID: PMC3671586 DOI: 10.1021/jp3053828] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complete and reversible charge-selective sequestration of fluorophores by a weak polyelectrolyte brush, poly(2-(dimethylamino)ethylmethacrylate) (PDMAEMA) was demonstrated using fluorescence correlation spectroscopy (FCS). The chemistry and thickness of the weak polyelectrolyte PDMAEMA was tuned reversibly between neutral and cationic polymer forms. Thus, by switching the pH successively, the brush architecture was tuned to selectively trap and release anionic dye probes while continuously excluding cationic molecules. In addition, line-scan FCS was implemented and applied for the first time to a synthetic polymer system and used to identify a new, slower diffusion time on the order of seconds for the sequestered anionic probe under acidic conditions. These results, which quantify the selective sequestration properties of the PDMAEMA brush, are important because they enable a better understanding of transport in polymers and establish a spectroscopic means of evaluating materials with proposed applications in separations science, charge storage/release, and environmental remediation.
Collapse
Affiliation(s)
- C R Daniels
- Department of Chemistry, Rice University, Houston, Texas 77251, USA
| | | | | | | | | |
Collapse
|
12
|
Fowlkes JD, Collier CP. Single-molecule mobility in confined and crowded femtolitre chambers. LAB ON A CHIP 2013; 13:877-885. [PMID: 23303284 DOI: 10.1039/c2lc40907k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The effects of increased crowding and confinement on the mobility of individual fluorescent molecules were studied using Fluorescence Correlation Spectroscopy (FCS) in a microfluidic device with sealable femtolitre-volume chambers, and compared to three dimensional stochastic Monte Carlo simulations. When crowding and the degree of confinement were increased simultaneously, extended correlation times of fluorescent intensity fluctuations were observed with FCS compared to varying either crowding or confinement alone. Both experimental data and simulation suggest these extended correlation times were due to increased fluorophore adsorption-desorption events at the chamber lid in the presence of crowders. The data in increasingly confined and crowded chambers described here captures some of the salient features of crowding in cell-like environments.
Collapse
Affiliation(s)
- Jason D Fowlkes
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | | |
Collapse
|
13
|
Koynov K, Butt HJ. Fluorescence correlation spectroscopy in colloid and interface science. Curr Opin Colloid Interface Sci 2012. [DOI: 10.1016/j.cocis.2012.09.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
14
|
Daniels CR, Kisley L, Kim H, Chen WH, Poongavanam MV, Reznik C, Kourentzi K, Willson RC, Landes CF. Fluorescence correlation spectroscopy study of protein transport and dynamic interactions with clustered-charge peptide adsorbents. J Mol Recognit 2012; 25:435-42. [PMID: 22811068 DOI: 10.1002/jmr.2206] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ion-exchange chromatography relies on electrostatic interactions between the adsorbent and the adsorbate and is used extensively in protein purification. Conventional ion-exchange chromatography uses ligands that are singly charged and randomly dispersed over the adsorbent, creating a heterogeneous distribution of potential adsorption sites. Clustered-charge ion exchangers exhibit higher affinity, capacity, and selectivity than their dispersed-charge counterparts of the same total charge density. In the present work, we monitored the transport behavior of an anionic protein near clustered-charge adsorbent surfaces using fluorescence correlation spectroscopy. We can resolve protein-free diffusion, hindered diffusion, and association with bare glass, agarose-coated, and agarose-clustered peptide surfaces, demonstrating that this method can be used to understand and ultimately optimize clustered-charge adsorbent and other surface interactions at the molecular scale.
Collapse
|
15
|
Abstract
Functional polymers have a wide variety of applications ranging from energy storage to drug delivery. For energy storage applications, desirable material properties include low cost, high charge storage and/or mobility, and low rates of degradation. Isotropic thin films have been used for many of these types of applications, but research suggests that different structures such as polymer brushes can improve charge transport by an order of magnitude. Supported polymer brush structures produced by "grafting-from" polymerization methods offer a framework for a controlled study of these materials on the molecular scale. Using these materials, researchers can study the basis of hindered diffusion because they contain a relatively homogeneous polyelectrolyte membrane. In addition, researchers can use fluorescent molecular probes with different charges to examine steric and Coulombic contributions to transport near and within polymer brushes. In this Account, we discuss recent progress in using fluorescence correlation spectroscopy, single-molecule polarization-resolved spectroscopy, and a novel three-dimensional orientational technique to understand the transport of charged dye probes interacting with the strong polyanionic brush, poly(styrene sulfonate). Our preliminary experiments demonstrate that a cationic dye, Rhodamine 6G, probes the brush as a counterion, and diffusion is therefore dominated by Coulombic forces, which results in a 10,000-fold decrease in the diffusion coefficient in comparison with free diffusion. We also support our experimental results with molecular dynamics simulations. Further experiments show that, up to 50% of the time, Rhodamine 6G translates within the brush without significant rotational diffusion, which indicates a strong deviation from Fickian transport mechanisms (in which translational and rotational diffusion are related directly through parameters such as chemical potential, size, solution viscosity, and thermal properties). To understand this oriented transport, we discuss the development of an experimental technique that allows us to quantify the three-dimensional orientation on the time scale of intrabrush transport. This method allowed us to identify a unique orientational transport direction for Rhodamine 6G within the poly(styrene sulfonate) brush and to report preliminary evidence for orientational dye "hopping".
Collapse
Affiliation(s)
- Carmen Reznik
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| |
Collapse
|
16
|
Daniels CR, Reznik C, Kilmer R, Felipe MJ, Tria MCR, Kourentzi K, Chen WH, Advincula RC, Willson RC, Landes CF. Permeability of anti-fouling PEGylated surfaces probed by fluorescence correlation spectroscopy. Colloids Surf B Biointerfaces 2011; 88:31-8. [PMID: 21742471 PMCID: PMC5625349 DOI: 10.1016/j.colsurfb.2011.05.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 05/20/2011] [Accepted: 05/21/2011] [Indexed: 10/18/2022]
Abstract
The present work reports on in situ observations of the interaction of organic dye probe molecules and dye-labeled protein with different poly(ethylene glycol) (PEG) architectures (linear, dendron, and bottle brush). Fluorescence correlation spectroscopy (FCS) and single molecule event analysis were used to examine the nature and extent of probe-PEG interactions. The data support a sieve-like model in which size-exclusion principles determine the extent of probe-PEG interactions. Small probes are trapped by more dense PEG architectures and large probes interact more with less dense PEG surfaces. These results, and the tunable pore structure of the PEG dendrons employed in this work, suggest the viability of electrochemically-active materials for tunable surfaces.
Collapse
Affiliation(s)
| | - Carmen Reznik
- Department of Chemistry, Rice University, Houston, TX 77251, United States
| | - Rachel Kilmer
- Department of Chemistry, Rice University, Houston, TX 77251, United States
| | - Mary Jane Felipe
- Department of Chemistry, University of Houston, Houston, TX 77004, United States
| | | | - Katerina Kourentzi
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, United States
| | - Wen-Hsiang Chen
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, United States
| | - Rigoberto C. Advincula
- Department of Chemistry, University of Houston, Houston, TX 77004, United States
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, United States
| | - Richard C. Willson
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, United States
| | - Christy F. Landes
- Department of Chemistry, Rice University, Houston, TX 77251, United States
| |
Collapse
|
17
|
Reznik C, Berg R, Foster E, Advincula R, Landes CF. Transient 3-Dimensional Orientation of Molecular Ions in an Ordered Polyelectrolyte Membrane. J Phys Chem Lett 2011; 2:10.1021/jz200065f. [PMID: 24371507 PMCID: PMC3871193 DOI: 10.1021/jz200065f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Single-molecule fluorescence spectroscopy is employed to reveal 3-dimensional details of the mechanisms underpinning ion transport in a polyelectrolyte thin film possessing polymer-brush nanoscale order. The ability to resolve fluorescence emission over three discrete polarization angles reveals that these ordered materials impart 3-dimensional orientation to charged, diffusing molecules. The experiments, supported by simulations, report global orientation parameters for molecular transport, track dipole angle progressions over time, and identify a unique transport mechanism: translational diffusion with restricted rotation. Generally, realization of this experimental method for translational diffusion in systems exhibiting basic orientation should lend itself to evaluation of transport in a variety of important, ordered, functional materials.
Collapse
Affiliation(s)
| | | | - Ed Foster
- University of Houston, Houston, Texas 77204
| | | | | |
Collapse
|