1
|
Ong Q, Xufeng X, Stellacci F. Versatile Capillary Cells for Handling Concentrated Samples in Analytical Ultracentrifugation. Anal Chem 2024; 96:2567-2573. [PMID: 38301115 PMCID: PMC10867799 DOI: 10.1021/acs.analchem.3c05006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 02/03/2024]
Abstract
In concentrated macromolecular dispersions, far-from-ideal intermolecular interactions determine the dispersion behaviors including phase transition, crystallization, and liquid-liquid phase separation. Here, we present a novel versatile capillary-cell design for analytical ultracentrifugation-sedimentation equilibrium (AUC-SE), ideal for studying samples at high concentrations. Current setups for such studies are difficult and unreliable to handle, leading to a low experimental success rate. The design presented here is easy to use, robust, and reusable for samples in both aqueous and organic solvents while requiring no special tools or chemical modification of AUC cells. The key and unique feature is the fabrication of liquid reservoirs directly on the bottom window of AUC cells, which can be easily realized by laser ablation or mechanical drilling. The channel length and optical path length are therefore tunable. The success rate for assembling this new cell is close to 100%. We demonstrate the practicality of this cell by studying: (1) the equation of state and second virial coefficients of concentrated gold nanoparticle dispersions in water and bovine serum albumin (BSA) as well as lysozyme solution in aqueous buffers, (2) the gelation phase transition of DNA and BSA solutions, and (3) liquid-liquid phase separation of concentrated BSA/polyethylene glycol (PEG) droplets.
Collapse
Affiliation(s)
- Quy Ong
- Laboratory Of Supramolecular
Nanomaterials And Interfaces, Ecole Polytechnique
Fédérale de Lausanne (EPFL), Station 12, 1015 Lausanne, Switzerland
| | - Xu Xufeng
- Laboratory Of Supramolecular
Nanomaterials And Interfaces, Ecole Polytechnique
Fédérale de Lausanne (EPFL), Station 12, 1015 Lausanne, Switzerland
| | - Francesco Stellacci
- Laboratory Of Supramolecular
Nanomaterials And Interfaces, Ecole Polytechnique
Fédérale de Lausanne (EPFL), Station 12, 1015 Lausanne, Switzerland
| |
Collapse
|
2
|
Dronova M, Lécolier E, Barré L, Michot LJ. Phase diagram, structure and rheology of boehmite dispersions: role of electrostatic interactions. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
3
|
Keita C, Hallez Y, Salmon JB. Microfluidic osmotic compression of a charge-stabilized colloidal dispersion: Equation of state and collective diffusion coefficient. Phys Rev E 2021; 104:L062601. [PMID: 35030960 DOI: 10.1103/physreve.104.l062601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
We show, using a model coupling mass transport and liquid theory calculations for a charge-stabilized colloidal dispersion, that diffusion significantly limits measurement times of its equation of state (EOS), osmotic pressure vs composition, using the osmotic compression technique. Following this result, we present a microfluidic chip allowing one to measure the entire EOS of a charged dispersion at the nanoliter scale in a few hours. We also show that time-resolved analyses of relaxation to equilibrium in this microfluidic experiment lead to direct estimates of the collective diffusion coefficient of the dispersion in Donnan equilibrium with a salt reservoir.
Collapse
Affiliation(s)
- Camille Keita
- CNRS, Solvay, LOF, UMR 5258, Université Bordeaux, F-33600 Pessac, France
| | - Yannick Hallez
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | | |
Collapse
|
4
|
Zemb T, Rosenberg R, Marčelja S, Haffke D, Dufrêche JF, Kunz W, Horinek D, Cölfen H. Phase separation of binary mixtures induced by soft centrifugal fields. Phys Chem Chem Phys 2021; 23:8261-8272. [PMID: 33527947 DOI: 10.1039/d0cp01527j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We use the model system ethanol-dodecane to demonstrate that giant critical fluctuations induced by easily accessible weak centrifugal fields as low as 2000g can be observed above the miscibility gap of a binary liquid mixture. Moreover, several degrees above the phase transition, i.e. in the one-phase region, strong gradients of ethanol concentration occur upon centrifugation. In this case, the standard interpretation of sedimentation equilibrium in the analytical ultracentrifuge (AUC) yields an apparent molar mass of ethanol three orders of magnitude higher than the real value. Notably, these composition gradients have no influence on the distribution gradient of solutes such as dyes like Nile red. The thick opaque interphase formed upon centrifugation does not appear as the commonly observed sharp meniscus, but as a turbidity zone, similar to critical opalescence. This layer is a few millimeters thick and separates two fluids with low compositional gradients. All these effects can be qualitatively understood and explained using the Flory-Huggins solution model coupled to classical density functional theory (DFT). In this domain hetero-phase fluctuations can be triggered by gravity even far from the critical point. Taking into account Jean Perrin's approach to external fields in colloids, a self-consistent definition of the Flory effective volume and an explicit calculation of the total free energy per unit volume is possible.
Collapse
Affiliation(s)
- Thomas Zemb
- Institute for Separation Chemistry ICSM U Montpellier/CEA/CNRS/ENSCM, Marcoule, France
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Xu X, Franke T, Schilling K, Sommerdijk NAJM, Cölfen H. Binary Colloidal Nanoparticle Concentration Gradients in a Centrifugal Field at High Concentration. NANO LETTERS 2019; 19:1136-1142. [PMID: 30644753 DOI: 10.1021/acs.nanolett.8b04496] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Binary colloidal nanoparticles have been found to form different types of crystalline phases at varied radial positions in a centrifugal field by Chen et al. ( ACS Nano 2015, 9, 6944-50). The variety of binary phase behaviors resulted from the two different nanoparticle concentration gradients, but to date, the gradients can only be empirically controlled. For the first time, we are able to measure, fit, and simulate binary hard-sphere colloidal nanoparticle concentration gradients at high particle concentrations up to 30 vol %, which enables tailor-made gradients in a centrifugal field. By this means, a continuous range of binary particle concentration ratios can be accessed in one single experiment to obtain an extended phase diagram. By dispersing two differently sized silica nanoparticles labeled with two different fluorescence dyes in a refractive index matching solvent, we can use a multi-wavelength analytical ultracentrifuge (MWL-AUC) to measure the individual concentration gradient for each particle size in sedimentation-diffusion equilibrium. The influence of the remaining slight turbidity at high concentration can be corrected using the MWL spectra from the AUC data. We also show that the experimental concentration gradients can be fitted using a noninteracting nonideal sedimentation model. By using these fitted parameters, we are able to simulate nanoparticle concentration gradients, which agreed with the subsequent experiments at a high concentration of 10 vol % and thus allowed for the simulation of binary concentration gradients of hard-sphere nanoparticles in preparative ultracentrifuges (PUCs). Finally we demonstrated that by simulating the concentration gradients in PUCs, a continuous and extended binary nanoparticle phase diagram can be obtained by simply studying the structure evolution along the centrifugal field for one single sample instead of a large number of experiments with discrete compositions as in conventional studies.
Collapse
Affiliation(s)
- X Xu
- Laboratory of Materials and Interface Chemistry & Centre for Multiscale Electron Microscopy , Eindhoven University of Technology , 5600 MB Eindhoven , The Netherlands
- Nanolytics GmbH , Am Mühlenberg 11 , 14476 Potsdam , Germany
- Physical Chemistry , University of Konstanz , Universitätsstraße 10, Box 714 , 78457 Konstanz , Germany
| | - T Franke
- Nanolytics GmbH , Am Mühlenberg 11 , 14476 Potsdam , Germany
| | - K Schilling
- Nanolytics GmbH , Am Mühlenberg 11 , 14476 Potsdam , Germany
| | - N A J M Sommerdijk
- Laboratory of Materials and Interface Chemistry & Centre for Multiscale Electron Microscopy , Eindhoven University of Technology , 5600 MB Eindhoven , The Netherlands
| | - H Cölfen
- Physical Chemistry , University of Konstanz , Universitätsstraße 10, Box 714 , 78457 Konstanz , Germany
| |
Collapse
|
6
|
Walter J, Thajudeen T, Süss S, Segets D, Peukert W. New possibilities of accurate particle characterisation by applying direct boundary models to analytical centrifugation. NANOSCALE 2015; 7:6574-87. [PMID: 25789666 DOI: 10.1039/c5nr00995b] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Analytical centrifugation (AC) is a powerful technique for the characterisation of nanoparticles in colloidal systems. As a direct and absolute technique it requires no calibration or measurements of standards. Moreover, it offers simple experimental design and handling, high sample throughput as well as moderate investment costs. However, the full potential of AC for nanoparticle size analysis requires the development of powerful data analysis techniques. In this study we show how the application of direct boundary models to AC data opens up new possibilities in particle characterisation. An accurate analysis method, successfully applied to sedimentation data obtained by analytical ultracentrifugation (AUC) in the past, was used for the first time in analysing AC data. Unlike traditional data evaluation routines for AC using a designated number of radial positions or scans, direct boundary models consider the complete sedimentation boundary, which results in significantly better statistics. We demonstrate that meniscus fitting, as well as the correction of radius and time invariant noise significantly improves the signal-to-noise ratio and prevents the occurrence of false positives due to optical artefacts. Moreover, hydrodynamic non-ideality can be assessed by the residuals obtained from the analysis. The sedimentation coefficient distributions obtained by AC are in excellent agreement with the results from AUC. Brownian dynamics simulations were used to generate numerical sedimentation data to study the influence of diffusion on the obtained distributions. Our approach is further validated using polystyrene and silica nanoparticles. In particular, we demonstrate the strength of AC for analysing multimodal distributions by means of gold nanoparticles.
Collapse
Affiliation(s)
- Johannes Walter
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Institute of Particle Technology (LFG), Cauerstr. 4, 91058 Erlangen, Germany.
| | | | | | | | | |
Collapse
|
7
|
Bauduin P, Zemb T. Perpendicular and lateral equations of state in layered systems of amphiphiles. Curr Opin Colloid Interface Sci 2014. [DOI: 10.1016/j.cocis.2014.02.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
8
|
Abstract
In this contribution the use of Analytical Ultracentrifugation (AUC) for the modern analysis of colloids is reviewed. Since AUC is a fractionation technique, distributions of the sedimentation coefficient, particle size and shape, molar mass and density can be obtained for particle sizes spanning the entire colloidal range. The Ångström resolution and the reliable statistics with which particle size distributions can be obtained from analytical ultracentrifugation makes this a high resolution analysis technique for the characterization of nanoparticles in solution or suspension. Several examples showing successful applications of AUC to complex problems in colloid science are given to illustrate the broad range and versatility of questions that can be answered by AUC experiments.
Collapse
Affiliation(s)
- Karel L Planken
- Max-Planck-Institute of Colloids and Interfaces, Colloid Chemistry, Research Campus Golm, Am Mühlenberg, D-14424 Potsdam, Germany.
| | | |
Collapse
|
9
|
Cölfen H, Laue TM, Wohlleben W, Schilling K, Karabudak E, Langhorst BW, Brookes E, Dubbs B, Zollars D, Rocco M, Demeler B. The Open AUC Project. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:347-59. [PMID: 19296095 PMCID: PMC2812709 DOI: 10.1007/s00249-009-0438-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 02/24/2009] [Accepted: 02/28/2009] [Indexed: 01/16/2023]
Abstract
Progress in analytical ultracentrifugation (AUC) has been hindered by obstructions to hardware innovation and by software incompatibility. In this paper, we announce and outline the Open AUC Project. The goals of the Open AUC Project are to stimulate AUC innovation by improving instrumentation, detectors, acquisition and analysis software, and collaborative tools. These improvements are needed for the next generation of AUC-based research. The Open AUC Project combines on-going work from several different groups. A new base instrument is described, one that is designed from the ground up to be an analytical ultracentrifuge. This machine offers an open architecture, hardware standards, and application programming interfaces for detector developers. All software will use the GNU Public License to assure that intellectual property is available in open source format. The Open AUC strategy facilitates collaborations, encourages sharing, and eliminates the chronic impediments that have plagued AUC innovation for the last 20 years. This ultracentrifuge will be equipped with multiple and interchangeable optical tracks so that state-of-the-art electronics and improved detectors will be available for a variety of optical systems. The instrument will be complemented by a new rotor, enhanced data acquisition and analysis software, as well as collaboration software. Described here are the instrument, the modular software components, and a standardized database that will encourage and ease integration of data analysis and interpretation software.
Collapse
Affiliation(s)
- Helmut Cölfen
- Colloid Chemistry, Max-Planck-Institute of Colloids and Interfaces, Research Campus Golm, Am Mühlenberg, 14424 Potsdam, Germany
| | - Thomas M. Laue
- Department of Biochemistry and Molecular Biology, University of New Hampshire, Durham, NH 03824 USA
| | | | - Kristian Schilling
- Nanolytics, Gesellschaft für Kolloidanalytik mbH, Am Mühlenberg 11, 14476 Potsdam, Germany
| | - Engin Karabudak
- Colloid Chemistry, Max-Planck-Institute of Colloids and Interfaces, Research Campus Golm, Am Mühlenberg, 14424 Potsdam, Germany
| | - Bradley W. Langhorst
- Department of Biochemistry and Molecular Biology, University of New Hampshire, Durham, NH 03824 USA
| | - Emre Brookes
- Department of Biochemistry, The University of Texas Health Science Center, San Antonio, TX 78229 USA
| | - Bruce Dubbs
- Department of Biochemistry, The University of Texas Health Science Center, San Antonio, TX 78229 USA
| | - Dan Zollars
- Department of Biochemistry, The University of Texas Health Science Center, San Antonio, TX 78229 USA
| | - Mattia Rocco
- Istituto Nazionale per la Ricerca sul Cancro (IST), 16132 Genova, Italy
| | - Borries Demeler
- Department of Biochemistry, The University of Texas Health Science Center, San Antonio, TX 78229 USA
| |
Collapse
|