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Minenkov A, Hollweger S, Duchoslav J, Erdene-Ochir O, Weise M, Ermilova E, Hertwig A, Schiek M. Monitoring the Electrochemical Failure of Indium Tin Oxide Electrodes via Operando Ellipsometry Complemented by Electron Microscopy and Spectroscopy. ACS APPLIED MATERIALS & INTERFACES 2024; 16:9517-9531. [PMID: 38324480 PMCID: PMC10895603 DOI: 10.1021/acsami.3c17923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/12/2024] [Accepted: 01/24/2024] [Indexed: 02/09/2024]
Abstract
Transparent conductive oxides such as indium tin oxide (ITO) are standards for thin film electrodes, providing a synergy of high optical transparency and electrical conductivity. In an electrolytic environment, the determination of an inert electrochemical potential window is crucial to maintain a stable material performance during device operation. We introduce operando ellipsometry, combining cyclic voltammetry (CV) with spectroscopic ellipsometry, as a versatile tool to monitor the evolution of both complete optical (i.e., complex refractive index) and electrical properties under wet electrochemical operational conditions. In particular, we trace the degradation of ITO electrodes caused by electrochemical reduction in a pH-neutral, water-based electrolyte environment during electrochemical cycling. With the onset of hydrogen evolution at negative bias voltages, indium and tin are irreversibly reduced to the metallic state, causing an advancing darkening, i.e., a gradual loss of transparency, with every CV cycle, while the conductivity is mostly conserved over multiple CV cycles. Post-operando analysis reveals the reductive (loss of oxygen) formation of metallic nanodroplets on the surface. The reductive disruption of the ITO electrode happens at the solid-liquid interface and proceeds gradually from the surface to the bottom of the layer, which is evidenced by cross-sectional transmission electron microscopy imaging and complemented by energy-dispersive X-ray spectroscopy mapping. As long as a continuous part of the ITO layer remains at the bottom, the conductivity is largely retained, allowing repeated CV cycling. We consider operando ellipsometry a sensitive and nondestructive tool to monitor early stage material and property changes, either by tracing failure points, controlling intentional processes, or for sensing purposes, making it suitable for various research fields involving solid-liquid interfaces and electrochemical activity.
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Affiliation(s)
- Alexey Minenkov
- Christian
Doppler Laboratory for Nanoscale Phase Transformations, Center for
Surface- and Nanoanalytics (ZONA), Johannes
Kepler University, A-4040 Linz, Austria
| | - Sophia Hollweger
- Center
for Surface- and Nanoanalytics (ZONA), Institute for Physical Chemistry
(IPC) & Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University, A-4040 Linz, Austria
| | - Jiri Duchoslav
- Christian
Doppler Laboratory for Nanoscale Phase Transformations, Center for
Surface- and Nanoanalytics (ZONA), Johannes
Kepler University, A-4040 Linz, Austria
| | - Otgonbayar Erdene-Ochir
- Center
for Surface- and Nanoanalytics (ZONA), Institute for Physical Chemistry
(IPC) & Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University, A-4040 Linz, Austria
| | - Matthias Weise
- FB 6.1
Oberflächenanalytik und Grenzflächenchemie, Bundesanstalt für Materialforschung und -prüfung
(BAM), Unter den Eichen
44-46, D-12203 Berlin, Germany
| | - Elena Ermilova
- FB 6.1
Oberflächenanalytik und Grenzflächenchemie, Bundesanstalt für Materialforschung und -prüfung
(BAM), Unter den Eichen
44-46, D-12203 Berlin, Germany
| | - Andreas Hertwig
- FB 6.1
Oberflächenanalytik und Grenzflächenchemie, Bundesanstalt für Materialforschung und -prüfung
(BAM), Unter den Eichen
44-46, D-12203 Berlin, Germany
| | - Manuela Schiek
- Center
for Surface- and Nanoanalytics (ZONA), Institute for Physical Chemistry
(IPC) & Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University, A-4040 Linz, Austria
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2
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Epiregulin as an Alternative Ligand for Leptin Receptor Alleviates Glucose Intolerance without Change in Obesity. Cells 2022; 11:cells11030425. [PMID: 35159237 PMCID: PMC8834548 DOI: 10.3390/cells11030425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/18/2022] [Accepted: 01/22/2022] [Indexed: 11/16/2022] Open
Abstract
The leptin receptor (LepR) acts as a signaling nexus for the regulation of glucose uptake and obesity, among other metabolic responses. The functional role of LepR under leptin-deficient conditions remains unclear. This study reports that epiregulin (EREG) governed glucose uptake in vitro and in vivo in Lepob mice by activating LepR under leptin-deficient conditions. Single and long-term treatment with EREG effectively rescued glucose intolerance in comparative insulin and EREG tolerance tests in Lepob mice. The immunoprecipitation study revealed binding between EREG and LepR in adipose tissue of Lepob mice. EREG/LepR regulated glucose uptake without changes in obesity in Lepob mice via mechanisms, including ERK activation and translocation of GLUT4 to the cell surface. EREG-dependent glucose uptake was abolished in Leprdb mice which supports a key role of LepR in this process. In contrast, inhibition of the canonical epidermal growth factor receptor (EGFR) pathway implicated in other EREG responses, increased glucose uptake. Our data provide a basis for understanding glycemic responses of EREG that are dependent on LepR unlike functions mediated by EGFR, including leptin secretion, thermogenesis, pain, growth, and other responses. The computational analysis identified a conserved amino acid sequence, supporting an evolutionary role of EREG as an alternative LepR ligand.
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Lee A, Mason ML, Lin T, Kumar SB, Kowdley D, Leung JH, Muhanna D, Sun Y, Ortega-Anaya J, Yu L, Fitzgerald J, DeVries AC, Nelson RJ, Weil ZM, Jiménez-Flores R, Parquette JR, Ziouzenkova O. Amino Acid Nanofibers Improve Glycemia and Confer Cognitive Therapeutic Efficacy to Bound Insulin. Pharmaceutics 2021; 14:pharmaceutics14010081. [PMID: 35056977 PMCID: PMC8778970 DOI: 10.3390/pharmaceutics14010081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/19/2021] [Accepted: 12/23/2021] [Indexed: 12/04/2022] Open
Abstract
Diabetes poses a high risk for debilitating complications in neural tissues, regulating glucose uptake through insulin-dependent and predominantly insulin-independent pathways. Supramolecular nanostructures provide a flexible strategy for combinatorial regulation of glycemia. Here, we compare the effects of free insulin to insulin bound to positively charged nanofibers comprised of self-assembling amino acid compounds (AACs) with an antioxidant-modified side chain moiety (AAC2) in both in vitro and in vivo models of type 1 diabetes. Free AAC2, free human insulin (hINS) and AAC2-bound-human insulin (AAC2-hINS) were tested in streptozotocin (STZ)-induced mouse model of type 1 diabetes. AAC2-hINS acted as a complex and exhibited different properties compared to free AAC2 or hINS. Mice treated with the AAC2-hINS complex were devoid of hypoglycemic episodes, had improved levels of insulin in circulation and in the brain, and increased expression of neurotransmitter taurine transporter, Slc6a6. Consequently, treatment with AAC2-hINS markedly advanced both physical and cognitive performance in mice with STZ-induced and genetic type 1 diabetes compared to treatments with free AAC2 or hINS. This study demonstrates that the flexible nanofiber AAC2 can serve as a therapeutic platform for the combinatorial treatment of diabetes and its complications.
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Affiliation(s)
- Aejin Lee
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.L.); (S.B.K.); (D.K.); (J.H.L.); (D.M.)
| | - McKensie L. Mason
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (M.L.M.); (T.L.); (Y.S.); (J.R.P.)
| | - Tao Lin
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (M.L.M.); (T.L.); (Y.S.); (J.R.P.)
| | - Shashi Bhushan Kumar
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.L.); (S.B.K.); (D.K.); (J.H.L.); (D.M.)
| | - Devan Kowdley
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.L.); (S.B.K.); (D.K.); (J.H.L.); (D.M.)
| | - Jacob H. Leung
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.L.); (S.B.K.); (D.K.); (J.H.L.); (D.M.)
| | - Danah Muhanna
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.L.); (S.B.K.); (D.K.); (J.H.L.); (D.M.)
| | - Yuan Sun
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (M.L.M.); (T.L.); (Y.S.); (J.R.P.)
| | - Joana Ortega-Anaya
- Department of Food Science and Technology, The Ohio State University, Columbus, OH 43210, USA; (J.O.-A.); (R.J.-F.)
| | - Lianbo Yu
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH 43210, USA;
| | - Julie Fitzgerald
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; (J.F.); (A.C.D.); (Z.M.W.)
| | - A. Courtney DeVries
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; (J.F.); (A.C.D.); (Z.M.W.)
- Department of Neuroscience, West Virginia University, Morgantown, WV 26506, USA
| | - Randy J. Nelson
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA;
| | - Zachary M. Weil
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; (J.F.); (A.C.D.); (Z.M.W.)
| | - Rafael Jiménez-Flores
- Department of Food Science and Technology, The Ohio State University, Columbus, OH 43210, USA; (J.O.-A.); (R.J.-F.)
| | - Jon R. Parquette
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (M.L.M.); (T.L.); (Y.S.); (J.R.P.)
| | - Ouliana Ziouzenkova
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA; (A.L.); (S.B.K.); (D.K.); (J.H.L.); (D.M.)
- Correspondence: ; Tel.: +1-614-292-5034
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Pogreb R, Grynyov R, Ben-Yosef O, Whyman G. Simultaneous determination of thickness and refractive index using Cauchy or Sellmeier formulas by the example of surface plasmon resonance study on ultrathin polysulfone film. INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION 2021. [DOI: 10.1080/1023666x.2021.1960703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Roman Pogreb
- Physics Department, Faculty of Natural Sciences, Ariel University, Ariel, Israel
| | - Roman Grynyov
- Physics Department, Faculty of Natural Sciences, Ariel University, Ariel, Israel
| | - Oz Ben-Yosef
- Physics Department, Faculty of Natural Sciences, Ariel University, Ariel, Israel
| | - Gene Whyman
- Physics Department, Faculty of Natural Sciences, Ariel University, Ariel, Israel
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Samarentsis AG, Pantazis AK, Tsortos A, Friedt JM, Gizeli E. Hybrid Sensor Device for Simultaneous Surface Plasmon Resonance and Surface Acoustic Wave Measurements. SENSORS 2020; 20:s20216177. [PMID: 33138312 PMCID: PMC7662402 DOI: 10.3390/s20216177] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 11/19/2022]
Abstract
Surface plasmon resonance (SPR) and Love wave (LW) surface acoustic wave (SAW) sensors have been established as reliable biosensing technologies for label-free, real-time monitoring of biomolecular interactions. This work reports the development of a combined SPR/LW-SAW platform to facilitate simultaneous optical and acoustic measurements for the investigation of biomolecules binding on a single surface. The system’s output provides recordings of two acoustic parameters, phase and amplitude of a Love wave, synchronized with SPR readings. We present the design and manufacturing of a novel experimental set-up employing, in addition to the SPR/LW-SAW device, a 3D-printed plastic holder combined with a PDMS microfluidic cell so that the platform can be used in a flow-through mode. The system was evaluated in a systematic study of the optical and acoustic responses for different surface perturbations, i.e., rigid mass loading (Au deposition), pure viscous loading (glycerol and sucrose solutions) and protein adsorption (BSA). Our results provide the theoretical and experimental basis for future application of the combined system to other biochemical and biophysical studies.
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Affiliation(s)
- Anastasios G. Samarentsis
- Institute of Molecular Biology & Biotechnology, FO.R.T.H, Vassilika Vouton, 70013 Heraklion, Greece; (A.G.S.); (A.T.)
- Department of Biology, University of Crete, Vassilika Vouton, 71409 Heraklion, Greece;
| | - Alexandros K. Pantazis
- Department of Biology, University of Crete, Vassilika Vouton, 71409 Heraklion, Greece;
- Institute of Electronic Structure & Laser, FO.R.T.H, Vassilika Vouton, 71409 Heraklion, Greece
| | - Achilleas Tsortos
- Institute of Molecular Biology & Biotechnology, FO.R.T.H, Vassilika Vouton, 70013 Heraklion, Greece; (A.G.S.); (A.T.)
| | - Jean-Michel Friedt
- SENSeOR SAS, Time and Frequency Department, FEMTO-ST Institute, 15B Avenue des Montboucons, 25030 Besançon, France;
| | - Electra Gizeli
- Institute of Molecular Biology & Biotechnology, FO.R.T.H, Vassilika Vouton, 70013 Heraklion, Greece; (A.G.S.); (A.T.)
- Department of Biology, University of Crete, Vassilika Vouton, 71409 Heraklion, Greece;
- Correspondence: ; Tel.: +30-2810-394373
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6
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Morphological and Mechanical Characterization of DNA SAMs Combining Nanolithography with AFM and Optical Methods. MATERIALS 2020; 13:ma13132888. [PMID: 32605060 PMCID: PMC7372444 DOI: 10.3390/ma13132888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/20/2020] [Accepted: 06/25/2020] [Indexed: 12/31/2022]
Abstract
The morphological and mechanical properties of thiolated ssDNA films self-assembled at different ionic strength on flat gold surfaces have been investigated using Atomic Force Microscopy (AFM). AFM nanoshaving experiments, performed in hard tapping mode, allowed selectively removing molecules from micro-sized regions. To image the shaved areas, in addition to the soft contact mode, we explored the use of the Quantitative Imaging (QI) mode. QI is a less perturbative imaging mode that allows obtaining quantitative information on both sample topography and mechanical properties. AFM analysis showed that DNA SAMs assembled at high ionic strength are thicker and less deformable than films prepared at low ionic strength. In the case of thicker films, the difference between film and substrate Young’s moduli could be assessed from the analysis of QI data. The AFM finding of thicker and denser films was confirmed by X-Ray Photoelectron Spectroscopy (XPS) and Spectroscopic Ellipsometry (SE) analysis. SE data allowed detecting the DNA UV absorption on dense monomolecular films. Moreover, feeding the SE analysis with the thickness data obtained by AFM, we could estimate the refractive index of dense DNA films.
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7
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Kananizadeh N, Lee J, Mousavi ES, Rodenhausen KB, Sekora D, Schubert M, Bartelt-Hunt S, Schubert E, Zhang J, Li Y. Deposition of titanium dioxide nanoparticles onto engineered rough surfaces with controlled heights and properties. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.03.088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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8
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Schwenzfeier KA, Erbe A, Bilotto P, Lengauer M, Merola C, Cheng HW, Mears LLE, Valtiner M. Optimizing multiple beam interferometry in the surface forces apparatus: Novel optics, reflection mode modeling, metal layer thicknesses, birefringence, and rotation of anisotropic layers. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:043908. [PMID: 31043001 DOI: 10.1063/1.5085210] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/25/2019] [Indexed: 05/26/2023]
Abstract
Multiple beam interferometry (MBI) evolved as a powerful tool for the simultaneous evaluation of thin film thicknesses and refractive indices in Surface Forces Apparatus (SFA) measurements. However, analysis has relied on simplifications for providing fast or simplified analysis of recorded interference spectra. Here, we describe the implementation of new optics and a generalized fitting approach to 4 × 4 transfer matrix method simulations for the SFA. Layers are described by dispersive complex refractive indices, thicknesses, and Euler angles that can be fitted, providing modeling for birefringent or colored layers. Normalization of data by incident light intensities is essential for the implementation of a fitting approach. Therefore, a modular optical system is described that can be retrofit to any existing SFA setup. Real-time normalization of spectra by white light is realized, alignment procedures are considerably simplified, and direct switching between transmission and reflection modes is possible. A numerical approach is introduced for constructing transfer matrices for birefringent materials. Full fitting of data to the simulation is implemented for arbitrary multilayered stacks used in SFA. This enables self-consistent fitting of mirror thicknesses, birefringence, and relative rotation of anisotropic layers (e.g., mica), evaluation of reflection and transmission mode spectra, and simultaneous fitting of thicknesses and refractive indices of media confined between two surfaces. In addition, a fast full spectral fitting method is implemented for providing a possible real-time analysis with up to 30 fps. We measure and analyze refractive indices of confined cyclohexane, the thickness of lipid bilayers, the thickness of metal layers, the relative rotation of birefringent materials, contact widths, as well as simultaneous fitting of both reflection and transmission mode spectra of typical interferometers. Our analyses suggest a number of best practices for conducting SFA and open MBI in an SFA for increasingly complex systems, including metamaterials, multilayered anisotropic layers, and chiral layers.
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Affiliation(s)
- Kai A Schwenzfeier
- Institute for Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Andreas Erbe
- Department of Material Science and Technology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Pierluigi Bilotto
- Institute for Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Maximilian Lengauer
- Institute for Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Claudia Merola
- Institute for Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Hsiu-Wei Cheng
- Institute for Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Laura L E Mears
- Institute for Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
| | - Markus Valtiner
- Institute for Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
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9
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Coupling Spectroscopic Ellipsometry and Quartz Crystal Microbalance to Study Organic Films at the Solid–Liquid Interface. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/978-3-319-75895-4_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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10
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Hinrichs K, Eichhorn KJ. Adsorption of Proteins at Solid Surfaces. ELLIPSOMETRY OF FUNCTIONAL ORGANIC SURFACES AND FILMS 2018. [PMCID: PMC7121624 DOI: 10.1007/978-3-319-75895-4_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karsten Hinrichs
- Leibniz-Institut für Analytische Wissenschaften – ISAS – e.V., Berlin, Germany
| | - Klaus-Jochen Eichhorn
- Abteilung Analytik, Leibniz-Institut für Polymerforschung Dresden e.V., Dresden, Sachsen Germany
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Kananizadeh N, Rice C, Lee J, Rodenhausen KB, Sekora D, Schubert M, Schubert E, Bartelt-Hunt S, Li Y. Combined quartz crystal microbalance with dissipation (QCM-D) and generalized ellipsometry (GE) to characterize the deposition of titanium dioxide nanoparticles on model rough surfaces. JOURNAL OF HAZARDOUS MATERIALS 2017; 322:118-128. [PMID: 27041442 DOI: 10.1016/j.jhazmat.2016.03.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/12/2016] [Accepted: 03/18/2016] [Indexed: 06/05/2023]
Abstract
Measuring the interactions between engineered nanoparticles and natural substrates (e.g. soils and sediments) has been very challenging due to highly heterogeneous and rough natural surfaces. In this study, three-dimensional nanostructured slanted columnar thin films (SCTFs), with well-defined roughness height and spacing, have been used to mimic surface roughness. Interactions between titanium dioxide nanoparticles (TiO2NP), the most extensively manufactured engineered nanomaterials, and SCTF coated surfaces were measured using a quartz crystal microbalance with dissipation monitoring (QCM-D). In parallel, in-situ generalized ellipsometry (GE) was coupled with QCM-D to simultaneously measure the amount of TiO2NP deposited on the surface of SCTF. While GE is insensitive to effects of mechanical water entrapment variations in roughness spaces, we found that the viscoelastic model, a typical QCM-D model analysis approach, overestimates the mass of deposited TiO2NP. This overestimation arises from overlaid frequency changes caused by particle deposition as well as additional water entrapment and partial water displacement upon nanoparticle adsorption. Here, we demonstrate a new approach to model QCM-D data, accounting for both viscoelastic effects and the effects of roughness-retained water. Finally, the porosity of attached TiO2NP layer was determined by coupling the areal mass density determined by QCM-D and independent GE measurements.
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Affiliation(s)
- Negin Kananizadeh
- Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Charles Rice
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Jaewoong Lee
- Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Department of Water Environmental Engineering Research, National Institute of Environmental Research 22755, Republic of Korea
| | - Keith B Rodenhausen
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Biolin Scientific, Inc., Paramus, NJ 07652, United States
| | - Derek Sekora
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Mathias Schubert
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Eva Schubert
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Shannon Bartelt-Hunt
- Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Yusong Li
- Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, United States; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, United States.
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12
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Peev D, Hofmann T, Kananizadeh N, Beeram S, Rodriguez E, Wimer S, Rodenhausen KB, Herzinger CM, Kasputis T, Pfaunmiller E, Nguyen A, Korlacki R, Pannier A, Li Y, Schubert E, Hage D, Schubert M. Anisotropic contrast optical microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:113701. [PMID: 27910407 DOI: 10.1063/1.4965878] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves sensitivity to a total mass required for detection by 4 orders of magnitude. We detail the design and operation principles of the anisotropic contrast optical microscope, and we present further applications to the detection of nanoparticles, to novel approaches for imaging chromatography and to new contrast modalities for observations on living cells.
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Affiliation(s)
- D Peev
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - T Hofmann
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - N Kananizadeh
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - S Beeram
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - E Rodriguez
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - S Wimer
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | | | - C M Herzinger
- J. A. Woollam Co., Inc., Lincoln, Nebraska 68508-2243, USA
| | - T Kasputis
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | - A Nguyen
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - R Korlacki
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - A Pannier
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Y Li
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - E Schubert
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - D Hage
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - M Schubert
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
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Solano I, Parisse P, Cavalleri O, Gramazio F, Casalis L, Canepa M. Investigating organic multilayers by spectroscopic ellipsometry: specific and non-specific interactions of polyhistidine with NTA self-assembled monolayers. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:544-53. [PMID: 27335745 PMCID: PMC4901546 DOI: 10.3762/bjnano.7.48] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/31/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND A versatile strategy for protein-surface coupling in biochips exploits the affinity for polyhistidine of the nitrilotriacetic acid (NTA) group loaded with Ni(II). Methods based on optical reflectivity measurements such as spectroscopic ellipsometry (SE) allow for label-free, non-invasive monitoring of molecule adsorption/desorption at surfaces. RESULTS This paper describes a SE study about the interaction of hexahistidine (His6) on gold substrates functionalized with a thiolate self-assembled monolayer bearing the NTA end group. By systematically applying the difference spectra method, which emphasizes the small changes of the ellipsometry spectral response upon the nanoscale thickening/thinning of the molecular film, we characterized different steps of the process such as the NTA-functionalization of Au, the adsorption of the His6 layer and its eventual displacement after reaction with competitive ligands. The films were investigated in liquid, and ex situ in ambient air. The SE investigation has been complemented by AFM measurements based on nanolithography methods (nanografting mode). CONCLUSION Our approach to the SE data, exploiting the full spectroscopic potential of the method and basic optical models, was able to provide a picture of the variation of the film thickness along the process. The combination of δΔ i +1 ,i (λ), δΨ i +1 ,i (λ) (layer-addition mode) and δΔ(†) i ', i +1(λ), δΨ(†) i ', i +1(λ) (layer-removal mode) difference spectra allowed us to clearly disentangle the adsorption of His6 on the Ni-free NTA layer, due to non specific interactions, from the formation of a neatly thicker His6 film induced by the Ni(II)-loading of the NTA SAM.
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Affiliation(s)
- Ilaria Solano
- Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, Genova, Italy
| | - Pietro Parisse
- Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163,5 in Area Science Park, Basovizza, Trieste, Italy
| | - Ornella Cavalleri
- Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, Genova, Italy
| | - Federico Gramazio
- Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, Genova, Italy
| | - Loredana Casalis
- Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163,5 in Area Science Park, Basovizza, Trieste, Italy
| | - Maurizio Canepa
- Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, Genova, Italy
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14
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Investigation of Bovine Serum Albumin (BSA) Attachment onto Self-Assembled Monolayers (SAMs) Using Combinatorial Quartz Crystal Microbalance with Dissipation (QCM-D) and Spectroscopic Ellipsometry (SE). PLoS One 2015; 10:e0141282. [PMID: 26505481 PMCID: PMC4624694 DOI: 10.1371/journal.pone.0141282] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/05/2015] [Indexed: 11/19/2022] Open
Abstract
Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various self-assembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The quantity of adsorbed bovine serum albumin protein increased with increasing bovine serum albumin concentration. After equilibrium sorption was reached at pH 7.0, desorption of bovine serum albumin occurred when pH was lowered to 2.0, which is below the isoelectric point of bovine serum albumin. Our data provide further evidence that combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry is a sensitive analytical tool to evaluate attachment and detachment of adsorbed proteins in systems with environmental implications.
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15
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Rodenhausen KB, Davis RS, Sekora D, Liang D, Mock A, Neupane R, Schmidt D, Hofmann T, Schubert E, Schubert M. The retention of liquid by columnar nanostructured surfaces during quartz crystal microbalance measurements and the effects of adsorption thereon. J Colloid Interface Sci 2015; 455:226-35. [DOI: 10.1016/j.jcis.2015.05.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/19/2015] [Accepted: 05/20/2015] [Indexed: 12/31/2022]
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16
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Zimmer A, Broch L, Boulanger C, Stein N. Growth Mechanism during the Early Stages of electrodeposition of Bismuth telluride films. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.05.190] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Kasputis T, Pieper A, Rodenhausen KB, Schmidt D, Sekora D, Rice C, Schubert E, Schubert M, Pannier AK. Use of precisely sculptured thin film (STF) substrates with generalized ellipsometry to determine spatial distribution of adsorbed fibronectin to nanostructured columnar topographies and effect on cell adhesion. Acta Biomater 2015; 18:88-99. [PMID: 25712389 DOI: 10.1016/j.actbio.2015.02.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 01/09/2015] [Accepted: 02/13/2015] [Indexed: 01/12/2023]
Abstract
Sculptured thin film (STF) substrates consist of nanocolumns with precise orientation, intercolumnar spacing, and optical anisotropy, which can be used as model biomaterial substrates to study the effect of homogenous nanotopogrophies on the three-dimensional distribution of adsorbed proteins. Generalized ellipsometry was used to discriminate between the distributions of adsorbed FN either on top of or within the intercolumnar void spaces of STFs, afforded by the optical properties of these precisely crafted substrates. Generalized ellipsometry indicated that STFs with vertical nanocolumns enhanced total FN adsorption two-fold relative to flat control substrates and the FN adsorption studies demonstrate different STF characteristics influence the degree of FN immobilization both on top and within intercolumnar spaces, with increasing spacing and surface area enhancing total protein adsorption. Mouse fibroblasts or mouse mesenchymal stem cells were subsequently cultured on STFs, to investigate the effect of highly ordered and defined nanotopographies on cell adhesion, spreading, and proliferation. All STF nanotopographies investigated in the absence of adsorbed FN were found to significantly enhance cell adhesion relative to flat substrates; and the addition of FN to STFs was found to have cell-dependent effects on enhancing cell-material interactions. Furthermore, the amount of FN adsorbed to the STFs did not correlate with comparative enhancements of cell-material interactions, suggesting that nanotopography predominantly contributes to the biocompatibility of homogenous nanocolumnar surfaces. This is the first study to correlate precisely defined nanostructured features with protein distribution and cell-nanomaterial interactions. STFs demonstrate immense potential as biomaterial surfaces for applications in tissue engineering, drug delivery, and biosensing.
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Affiliation(s)
- Tadas Kasputis
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Alex Pieper
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Keith Brian Rodenhausen
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Daniel Schmidt
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Singapore Synchotron Light Source, National University of Singapore, 119077, Singapore; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Derek Sekora
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Charles Rice
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Eva Schubert
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Mathias Schubert
- Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Angela K Pannier
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Mary and Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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18
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Willott JD, Murdoch TJ, Humphreys BA, Edmondson S, Wanless EJ, Webber GB. Anion-specific effects on the behavior of pH-sensitive polybasic brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3707-3717. [PMID: 25768282 DOI: 10.1021/acs.langmuir.5b00116] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The anion-specific solvation and conformational behavior of weakly basic poly(2-dimethylamino)ethyl methacrylate (poly(DMA)), poly(2-diethylamino)ethyl methacrylate (poly(DEA)), and poly(2-diisopropylamino)ethyl methacrylate (poly(DPA)) brushes, with correspondingly increasing inherent hydrophobicity, have been investigated using in situ ellipsometric and quartz crystal microbalance with dissipation (QCM-D) measurements. In the osmotic brush regime, as the initial low concentration of salt is increased, the brushes osmotically swell by the uptake of solvent as they become charged and the attractive hydrophobic inter- and intrachain interactions are overcome. With increased ionic strength, the brushes move into the salted brush regime where they desolvate and collapse as their electrostatic charge is screened. Here, as the brushes collapse, they transition to more uniform and rigid conformations, which dissipate less energy, than similarly solvated brushes at lower ionic strength. Significantly, in these distinct regimes brush behavior is not only ionic strength dependent but is also influenced by the nature of the added salt based on its position in the well-known Hofmeister or lyotropic series, with potassium acetate, nitrate, and thiocyanate investigated. The strongly kosmotropic acetate anions display low affinity for the hydrophobic polymers, and largely unscreened electrosteric repulsions allow the brushes to remain highly solvated at higher acetate concentrations. The mildly chaotropic nitrate and strongly chaotropic thiocyanate anions exhibit a polymer hydrophobicity-dependent affinity for the brushes. Increasing thiocyanate concentration causes the brushes to collapse at lower ionic strength than for the other two anions. This study of weak polybasic brushes demonstrates the importance of all ion, solvent, and polymer interactions.
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Affiliation(s)
- Joshua D Willott
- †Priority Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Timothy J Murdoch
- †Priority Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ben A Humphreys
- †Priority Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Steve Edmondson
- ‡School of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Erica J Wanless
- †Priority Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Grant B Webber
- †Priority Research Centre for Advanced Particle Processing and Transport, University of Newcastle, Callaghan, NSW 2308, Australia
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19
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Ogieglo W, Wormeester H, Eichhorn KJ, Wessling M, Benes NE. In situ ellipsometry studies on swelling of thin polymer films: A review. Prog Polym Sci 2015. [DOI: 10.1016/j.progpolymsci.2014.09.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Solano I, Parisse P, Gramazio F, Cavalleri O, Bracco G, Castronovo M, Casalis L, Canepa M. Spectroscopic ellipsometry meets AFM nanolithography: about hydration of bio-inert oligo(ethylene glycol)-terminated self assembled monolayers on gold. Phys Chem Chem Phys 2015; 17:28774-81. [PMID: 26445913 DOI: 10.1039/c5cp04028k] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An accurate thickness determination provides insight into the complex vertical morphology of OEG-terminated SAMs.
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Affiliation(s)
- Ilaria Solano
- Dipartimento di Fisica
- Università di Genova and CNISM
- Genova
- Italy
| | | | | | | | | | - Matteo Castronovo
- Department of Medical and Biological Sciences – University of Udine
- Udine
- Italy
| | | | - Maurizio Canepa
- Dipartimento di Fisica
- Università di Genova and CNISM
- Genova
- Italy
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21
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Willott JD, Humphreys BA, Murdoch TJ, Edmondson S, Webber GB, Wanless EJ. Hydrophobic effects within the dynamic pH-response of polybasic tertiary amine methacrylate brushes. Phys Chem Chem Phys 2015; 17:3880-90. [DOI: 10.1039/c4cp05292g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Monomer hydrophobicity dominates the kinetics of the pH-response of tertiary amine methacrylate brushes as determined by in situ ellipsometry and QCM-D kinetic and equilibrium measurements.
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Affiliation(s)
- Joshua D. Willott
- Priority Research Centre for Advanced Particle Processing and Transport
- University of Newcastle
- Callaghan
- Australia
| | - Ben A. Humphreys
- Priority Research Centre for Advanced Particle Processing and Transport
- University of Newcastle
- Callaghan
- Australia
| | - Timothy J. Murdoch
- Priority Research Centre for Advanced Particle Processing and Transport
- University of Newcastle
- Callaghan
- Australia
| | | | - Grant B. Webber
- Priority Research Centre for Advanced Particle Processing and Transport
- University of Newcastle
- Callaghan
- Australia
| | - Erica J. Wanless
- Priority Research Centre for Advanced Particle Processing and Transport
- University of Newcastle
- Callaghan
- Australia
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22
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Salamifar SE, Lai RY. Application of electrochemical surface plasmon resonance spectroscopy for characterization of electrochemical DNA sensors. Colloids Surf B Biointerfaces 2014; 122:835-839. [DOI: 10.1016/j.colsurfb.2014.07.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/05/2014] [Accepted: 07/16/2014] [Indexed: 11/25/2022]
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23
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Rodenhausen KB, Schmidt D, Rice C, Hofmann T, Schubert E, Schubert M. Detection of Organic Attachment onto Highly Ordered Three-Dimensional Nanostructure Thin Films by Generalized Ellipsometry and Quartz Crystal Microbalance with Dissipation Techniques. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/978-3-642-40128-2_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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24
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Hinrichs K, Eichhorn KJ. Adsorption of Proteins at Solid Surfaces. ELLIPSOMETRY OF FUNCTIONAL ORGANIC SURFACES AND FILMS 2014. [PMCID: PMC7121270 DOI: 10.1007/978-3-642-40128-2_2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Ellipsometry has a very high thin film sensitivity and can resolve sub-nm changes in the thickness of a protein film on a solid substrates. Being a technique based on photons in and photons out it can also be applied at solid-liquid interfaces. Ellipsometry has therefore found many in situ applications on protein layer dynamics but studies of protein layer structure are also frequent. Numerous ex situ applications on detection and quantification of protein layers are found and several biosensing concepts have been proposed. In this chapter, the use of ellipsometry in the above mentioned areas is reviewed and experimental methodology including cell design is briefly discussed. The classical ellipsometric challenge to determine both thickness and refractive index of a thin film is addressed and an overview of strategies to determine surface mass density is given. Included is also a discussion about spectral representations of optical properties of a protein layer in terms of a model dielectric function concept and its use for analysis of protein layer structure.
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Affiliation(s)
- Karsten Hinrichs
- Leibniz Institute for Analytical Sciences - ISAS - e. V., Berlin, Germany
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25
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Coupling Spectroscopic Ellipsometry and Quartz Crystal Microbalance to Study Organic Films at the Solid-Liquid Interface. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/978-3-642-40128-2_11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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26
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Granqvist N, Liang H, Laurila T, Sadowski J, Yliperttula M, Viitala T. Characterizing ultrathin and thick organic layers by surface plasmon resonance three-wavelength and waveguide mode analysis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:8561-8571. [PMID: 23758623 DOI: 10.1021/la401084w] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A three-wavelength angular-scanning surface plasmon resonance based analysis has been utilized for characterizing optical properties of organic nanometer-thick layers with a wide range of thicknesses. The thickness and refractive index were determined for sample layers with thicknesses ranging from subnanometer to hundreds of nanometers. The analysis approach allows for simultaneous determination of both the refractive index and thickness without prior knowledge of either the refractive index or the thickness of the sample layers and without the help of other instruments, as opposed to current methods and approaches for characterizing optical properties of organic nanometer-thick layers. The applicability of the three-wavelength angular-scanning surface plasmon resonance approach for characterizing thin and thick organic layers was demonstrated by ex situ deposited mono- and multilayers of stearic acid and hydrogenated soy phosphatidylcholine and in situ layer-by-layer deposition of two different polyelectrolyte multilayer systems. In addition to the three-wavelength angular-scanning surface plasmon resonance approach, another surface plasmon resonance optical phenomenon, i.e., the surface plasmon resonance waveguide mode, was utilized to characterize organic sample layers whose thicknesses border the micrometer scale. This was demonstrated by characterizing both in situ layer-by-layer deposited polyelectrolyte multilayer systems and an ex situ deposited spin-coated polymer layer.
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Affiliation(s)
- Niko Granqvist
- Faculty of Pharmacy, Division of Biopharmaceutics and Pharmacokinetics, University of Helsinki, 00014 Helsinki, Finland
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27
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In situ spectroscopic ellipsometry of pH-responsive polymer brushes on gold substrates. Anal Bioanal Chem 2013; 405:9061-9. [DOI: 10.1007/s00216-013-7090-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/15/2013] [Accepted: 05/22/2013] [Indexed: 10/26/2022]
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Konradi R, Textor M, Reimhult E. Using complementary acoustic and optical techniques for quantitative monitoring of biomolecular adsorption at interfaces. BIOSENSORS-BASEL 2012; 2:341-76. [PMID: 25586027 PMCID: PMC4263558 DOI: 10.3390/bios2040341] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 08/27/2012] [Accepted: 09/03/2012] [Indexed: 11/17/2022]
Abstract
The great wealth of different surface sensitive techniques used in biosensing, most of which claim to measure adsorbed mass, can at first glance look unnecessary. However, with each technique relying on a different transducer principle there is something to be gained from a comparison. In this tutorial review, different optical and acoustic evanescent techniques are used to illustrate how an understanding of the transducer principle of each technique can be exploited for further interpretation of hydrated and extended polymer and biological films. Some of the most commonly used surface sensitive biosensor techniques (quartz crystal microbalance, optical waveguide spectroscopy and surface plasmon resonance) are briefly described and five case studies are presented to illustrate how different biosensing techniques can and often should be combined. The case studies deal with representative examples of adsorption of protein films, polymer brushes and lipid membranes, and describe e.g., how to deal with strongly vs. weakly hydrated films, large conformational changes and ordered layers of biomolecules. The presented systems and methods are compared to other representative examples from the increasing literature on the subject.
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Affiliation(s)
- Rupert Konradi
- BASF SE, Advanced Materials and Systems Research, D-67056 Ludwigshafen, Germany.
| | - Marcus Textor
- Laboratory for Surface Science and Technology, Department of Materials, Swiss Federal Institute of Technology (ETH) Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland.
| | - Erik Reimhult
- Laboratory for Biologically inspired materials, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna, A-1190 Vienna, Austria.
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Bodvik R, Macakova L, Karlson L, Thormann E, Claesson P. Temperature-dependent competition between adsorption and aggregation of a cellulose ether--simultaneous use of optical and acoustical techniques for investigating surface properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:9515-9525. [PMID: 22621259 DOI: 10.1021/la301114f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Adsorption of the temperature-responsive polymer hydroxypropylmethylcellulose (HPMC) from an aqueous solution onto hydrophobized silica was followed well above the bulk instability temperature (T(2)) in temperature cycle experiments. Two complementary techniques, QCM-D and ellipsometry, were utilized simultaneously to probe the same substrate immersed in polymer solution. The interfacial processes were correlated with changes in polymer aggregation and viscosity of polymer solutions, as monitored by light scattering and rheological measurements. The simultaneous use of ellipsometry and QCM-D, and the possibility to follow layer properties up to 80 °C, well above the T(2) temperature, are both novel developments. A moderate increase in adsorbed amount with temperature was found below T(2), whereas a significant increase in the adsorbed mass and changes in layer properties were observed around the T(2) temperature where the bulk viscosity increases significantly. Thus, there is a clear correlation between transition temperatures in the adsorbed layer and in bulk solution, and we discuss this in relation to a newly proposed model that considers competition between aggregation and adsorption/deposition. A much larger temperature response above the T(2) temperature was found for adsorbed layers of HPMC than for layers of methyl cellulose. Possible reasons for this are discussed.
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Affiliation(s)
- Rasmus Bodvik
- Department of Chemistry, Surface and Corrosion Science, Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
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30
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Rodenhausen KB, Schmidt D, Kasputis T, Pannier AK, Schubert E, Schubert M. Generalized ellipsometry in-situ quantification of organic adsorbate attachment within slanted columnar thin films. OPTICS EXPRESS 2012; 20:5419-5428. [PMID: 22418349 DOI: 10.1364/oe.20.005419] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We apply generalized ellipsometry, well-known to be sensitive to the optical properties of anisotropic materials, to determine the amount of fibronectin protein that adsorbs onto a Ti slanted columnar thin film from solution. We find that the anisotropic optical properties of the thin film change upon organic adsorption. An optical model for ellipsometry data analysis incorporates an anisotropic Bruggeman effective medium approximation. We find that differences in experimental data from before and after fibronectin adsorption can be solely attributable to the uptake of fibronectin within the slanted columnar thin film. Simultaneous, in-situ generalized ellipsometry and quartz crystal microbalance measurements show excellent agreement on the amount and rate of fibronectin adsorption. Quantitative characterization of organic materials within three-dimensional, optically anisotropic slanted columnar thin films could permit their use in optical sensor applications.
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Affiliation(s)
- Keith B Rodenhausen
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, 207 Othmer Hall, Lincoln, NE 68588, USA.
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