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Yuan X, Wolf N, Mayer D, Offenha Usser A, Wo Rdenweber R. Vapor-Phase Deposition and Electronic Characterization of 3-Aminopropyltriethoxysilane Self-Assembled Monolayers on Silicon Dioxide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:8183-8190. [PMID: 31144819 DOI: 10.1021/acs.langmuir.8b03832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Although organosilanes, especially 3-aminopropyltriethoxysilane (APTES), are commonly used to functionalize oxide substrates for a variety of applications ranging from molecular/biosensors and electronics to protective layers, reliable and controlled deposition of these molecules remains a major obstacle. In this study, we use surface potential analyses to record and optimize the gas-phase deposition of APTES self-assembled monolayers (SAMs) and to determine the resulting change of the electrokinetic potential and charge at the solid?liquid interface when the system is exposed to an electrolyte. Using a gas-phase molecular layer deposition setup with an in situ molecule deposition sensor, APTES is deposited at room temperature onto ozone-activated SiO2. The resulting layers are characterized using various techniques ranging from contact angle analysis, ellipsometry, fluorescence microscopy, X-ray photoelectron spectroscopy, and electrokinetic analysis to AFM. It turns out that adequate postdeposition treatment is crucial to the formation of perfect molecular SAMs. We demonstrate how a thick layer of APTES molecules is initially adsorbed at the surface; however, the molecules do not bind to SiO2 and are removed if the film is exposed to an electrolyte. Only if the film is kept in a gaseous environment (preferable at low pressure) for a long enough time do APTES molecules start to bind to the surface and form the SAM layer. During this time, superfluous molecules are removed. The resulting modification of the electrokinetic potential at the surface is analyzed in detail for different states.
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Affiliation(s)
- Xiaobo Yuan
- Institute of Complex Systems?Bioelectronics (ICS-8) , Forschungszentrum Ju?lich , Ju?lich 52428 , Germany
| | - Nikolaus Wolf
- Institute of Complex Systems?Bioelectronics (ICS-8) , Forschungszentrum Ju?lich , Ju?lich 52428 , Germany
| | - Dirk Mayer
- Institute of Complex Systems?Bioelectronics (ICS-8) , Forschungszentrum Ju?lich , Ju?lich 52428 , Germany
| | - Andreas Offenha Usser
- Institute of Complex Systems?Bioelectronics (ICS-8) , Forschungszentrum Ju?lich , Ju?lich 52428 , Germany
| | - Roger Wo Rdenweber
- Institute of Complex Systems?Bioelectronics (ICS-8) , Forschungszentrum Ju?lich , Ju?lich 52428 , Germany
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2
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Fajín JLC, Teixeira F, Gomes JRB, Cordeiro MNDS. Effect of van der Waals interactions in the DFT description of self-assembled monolayers of thiols on gold. Theor Chem Acc 2015. [DOI: 10.1007/s00214-015-1666-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Lamb BM, Luo W, Nagdas S, Yousaf MN. Cell division orientation on biospecific peptide gradients. ACS APPLIED MATERIALS & INTERFACES 2014; 6:11523-11528. [PMID: 25007410 DOI: 10.1021/am502209k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An assay was developed for determining cell division orientation on gradients. The methodology is based on permeating microfluidic devices with alkanethiols and subsequent printing of cell adhesive peptide gradient self-assembled monolayers (SAMs) for examining oriented cell divisions. To our knowledge, there has been no study examining the correlation between cell division orientations based on an underlying ligand gradient. These results implicate an important role for how the extracellular matrix may control cell division. These surfaces would allow for a range of cell behavior (polarization, migration, division, differentiation) studies on tailored biospecific gradients and as a potential biotechnological platform to assess small molecule perturbations of cell function.
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Affiliation(s)
- Brian M Lamb
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
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4
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Gooding JJ, Parker SG, Lu Y, Gaus K. Molecularly engineered surfaces for cell biology: from static to dynamic surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3290-3302. [PMID: 24228944 DOI: 10.1021/la4037919] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Surfaces with a well-defined presentation of ligands for receptors on the cell membrane can serve as models of the extracellular matrix for studying cell adhesion or as model cell surfaces for exploring cell-cell contacts. Because such surfaces can provide exquisite control over, for example, the density of these ligands or when the ligands are presented to the cell, they provide a very precise strategy for understanding the mechanisms by which cells respond to external adhesive cues. In the present feature article, we present an overview of the basic biology of cell adhesion before discussing surfaces that have a static presentation of immobile ligands. We outline the biological information that such surfaces have given us, before progressing to recently developed switchable surfaces and surfaces that mimic the lipid bilayer, having adhesive ligands that can move around the membrane and be remodeled by the cell. Finally, the feature article closes with some of the biological information that these new types of surfaces could provide.
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Affiliation(s)
- J Justin Gooding
- The Australian Centre for NanoMedicine, ‡School of Chemistry, and §Centre for Vascular Research, The University of New South Wales , Sydney 2052, Australia
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5
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Lee EJ, Chan EWL, Luo W, Yousaf MN. Ligand slope, density and affinity direct cell polarity and migration on molecular gradient surfaces. RSC Adv 2014. [DOI: 10.1039/c4ra03795b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A patterned peptide gradient with control of slope and density is created for studies of directed cell polarization and migration.
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Affiliation(s)
- Eun-ju Lee
- Department of Chemistry
- The University of North Carolina at Chapel Hill
- Chapel Hill, USA
| | - Eugene W. L. Chan
- Department of Chemistry
- The University of North Carolina at Chapel Hill
- Chapel Hill, USA
| | - Wei Luo
- Department of Chemistry
- The University of North Carolina at Chapel Hill
- Chapel Hill, USA
- Department of Chemistry and Biology
- Centre for Research in Biomolecular Interaction
| | - Muhammad N. Yousaf
- Department of Chemistry
- The University of North Carolina at Chapel Hill
- Chapel Hill, USA
- Department of Chemistry and Biology
- Centre for Research in Biomolecular Interaction
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6
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Ross AM, Lahann J. Surface engineering the cellular microenvironment via patterning and gradients. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/polb.23275] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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7
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Luo W, Yousaf MN. Biomolecular modification of carbon nanotubes for studies of cell adhesion and migration. NANOTECHNOLOGY 2011; 22:494019. [PMID: 22101926 DOI: 10.1088/0957-4484/22/49/494019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report a strategy for tailoring and patterning carbon nanotubes (CNTs) for biospecific cell studies. We synthesized a new electroactive hydroquinone terminated pyrene molecule to tailor CNTs. These modified CNTs can be oxidized and chemoselectively reacted with oxyamine tethered ligands to generate various ligand tethered CNTs. A cell adhesive Arg-Gly-Asp peptide (RGD) is immobilized to the CNTs and a new microfluidic patterning method is employed to generate multiplex patterned surfaces for biospecific cell adhesion and migration studies. This work demonstrates the integration of a new functionalization strategy to immobilize a variety of ligands to CNTs for a range of potential drug delivery, tissue imaging and cellular behavior studies and a microfluidic patterning strategy for generating complex high-throughput surfaces for biotechnological and cell based assay applications.
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Affiliation(s)
- Wei Luo
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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8
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Dutta D, Pulsipher A, Luo W, Mak H, Yousaf MN. Engineering cell surfaces via liposome fusion. Bioconjug Chem 2011; 22:2423-33. [PMID: 22054009 DOI: 10.1021/bc200236m] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In this study, we have rewired cell surfaces with ketone and oxyamine molecules based on liposome fusion for applications in cell-surface engineering. Lipid vesicles, functionalized with ketone and oxyamine molecules, display complementary chemistry and undergo recognition, docking, and subsequent fusion upon covalent oxime bond formation. Liposome fusion was characterized by several techniques including matrix-assisted laser-desorption/ionization mass spectrometry (MALDI-MS), light scattering, fluorescence resonance energy transfer (FRET), and transmission electron microscopy (TEM). When cultured with cells, ketone- and oxyamine-containing liposomes undergo spontaneous membrane fusion to present the respective molecules from cell surfaces. Ketone-functionalized cell surfaces serve as sites for chemoselective ligation with oxyamine-conjugated molecules. We tailored and fluorescently labeled cell surfaces with an oxyamine-conjugated rhodamine dye. As an application of this cell-surface engineering strategy, ketone- and oxyamine-functionalized cells were patterned on oxyamine- and ketone-presenting surfaces, respectively. Cells adhered, spread, and proliferated in the patterned regions via interfacial oxime linkage. The number of ketone molecules on the cell surface was also quantified by flow cytometry.
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Affiliation(s)
- Debjit Dutta
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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9
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Prakash S, Karacor MB. Characterizing stability of "click" modified glass surfaces to common microfabrication conditions and aqueous electrolyte solutions. NANOSCALE 2011; 3:3309-3315. [PMID: 21766099 DOI: 10.1039/c1nr10261c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Microfluidic and nanofluidic systems are dominated by fluid-wall interactions due to enormous surface-area-to-volume ratios in these devices. Therefore, strategies to control wall properties in a reliable and repeatable manner can be important for device operation. Chemical modification of surfaces provides one such method. However, the stability of the surface adhered layers under fabrication and likely device operating conditions have not been evaluated in depth. This paper presents the stability analysis of three surface layers used in the 'click' chemistry methodology for surface modification. The three surface layers have bromo, amine, and methyl termination on glass surfaces. All three surface groups are exposed to various wet and dry conditions including acid, base, solvent, electrolyte buffer solutions, oxidative plasmas, UV light, and thermal processing conditions. Contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy were used to quantify the stability of the adhered surface layers. The data show that the brominated surface was stable to most test conditions, while both the amine and methyl surface layers were stable to a narrower set of test conditions.
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Affiliation(s)
- Shaurya Prakash
- Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Avenue, Columbus, Ohio 43210, USA.
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10
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Dutta D, Pulsipher A, Luo W, Yousaf MN. Synthetic Chemoselective Rewiring of Cell Surfaces: Generation of Three-Dimensional Tissue Structures. J Am Chem Soc 2011; 133:8704-13. [DOI: 10.1021/ja2022569] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Debjit Dutta
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Abigail Pulsipher
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Wei Luo
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Muhammad N. Yousaf
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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11
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Schneider MH, Tran Y, Tabeling P. Benzophenone absorption and diffusion in poly(dimethylsiloxane) and its role in graft photo-polymerization for surface modification. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1232-40. [PMID: 21207954 DOI: 10.1021/la103345k] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Following the great success of traditional microfluidic devices across many disciplines, a new class of microfluidic systems emerged in recent years, which features finely tuned, localized surface modifications within the microstructures in order to keep up with the demand for devices of ever increasing complexity (lab on chip, assay on chip, etc.). Graft photopolymerization has become a powerful tool for such localized surface modifications particularly in combination with poly(dimethylsiloxane) (PDMS) devices, as it is compatible with many functional monomers and allows for high spatial resolution. However, application within enclosed PDMS microstructures and in particular well-controlled surface-directed polymerization remains challenging. Detailed understanding of the interaction between photoinitiator, benzophenone (BP), and polymer matrix is needed. We have developed a visualization technique, which allows for observation of reacted BP in situ within the PDMS matrix. We present a detailed study on solvent-driven BP diffusion providing results essential to successful surface treatment. We also identified and investigated photoinitiator inhibition by oxygen and provide appropriate mitigation strategies.
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Affiliation(s)
- Marc H Schneider
- Microfluidique, MEMS & Nanostructures, UMR 7083 Gulliver CNRS-ESPCI, Paris, France
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12
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Affiliation(s)
- Rahul Bhure
- Center for Materials Research (CMR), Center for Biotechnology and Biomedical Sciences (CBBS), Department of Chemistry, Norfolk State University (NSU), Norfolk, VA 23504
| | - Anil Mahapatro
- Center for Materials Research (CMR), Center for Biotechnology and Biomedical Sciences (CBBS), Department of Chemistry, Norfolk State University (NSU), Norfolk, VA 23504
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13
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Lamb BM, Park S, Yousaf MN. Microfluidic permeation printing of self-assembled monolayer gradients on surfaces for chemoselective ligand immobilization applied to cell adhesion and polarization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:12817-12823. [PMID: 20586451 DOI: 10.1021/la1022642] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
To study complex cell behavior on model surfaces requires biospecific interactions between the interfacing cell and material. Developing strategies to pattern well-defined molecular gradients on surfaces is difficult but critical for studying cell adhesion, polarization, and directed cell migration. We introduce a new strategy, microfluidic SPREAD (Solute PeRmeation Enhancement And Diffusion) for inking poly(dimethylsiloxane) (PDMS) microfluidic cassettes with a gradient of alkanethiol. Using SPREAD, an oxyamine-terminated alkanethiol is able to permeate into a PDMS microfluidic cassette, creating a chemical gradient, which can subsequently be transfer printed onto a gold surface to form the corresponding chemoselective gradient of oxyamine-alkanethiol self-assembled monolayer (SAM). By first patterning regions of the gold surface with a protective SAM using microfluidic lithography, directional gradients can be stamped exclusively onto unprotected bare gold regions to form single cell gradient microarrays. The microfluidic SPREAD strategy can also be extended to print micrometer-sized islands of radial SAM gradients with excellent geometric resolution. The immobilization of a cell adhesive Arg-Gly-Asp (RGD)-ketone peptide to the SPREAD stamped oxyamine-alkanethiol SAMs provides a stable interfacial oxime linkage for biospecific studies of cell adhesion, polarity, and migration.
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Affiliation(s)
- Brian M Lamb
- Department of Chemistry and the Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA
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14
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Pulsipher A, Yousaf MN. Surface chemistry and cell biological tools for the analysis of cell adhesion and migration. Chembiochem 2010; 11:745-53, 730. [PMID: 20198673 DOI: 10.1002/cbic.200900787] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Abigail Pulsipher
- Department of Chemistry and the Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA
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15
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Dutta D, Pulsipher A, Yousaf MN. Selective tethering of ligands and proteins to a microfluidically patterned electroactive fluid lipid bilayer array. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:9835-9841. [PMID: 20131880 DOI: 10.1021/la1001545] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report a new, quantitative methodology to pattern and present ligands from planar, supported, fluid lipid bilayers. By combining microfluidic lithography (microFL) with an electroactive, chemoselective interfacial reaction strategy, a number of ligands as well as protein concanavalin A were immobilized in lipid microarrays. Electroactive vesicles were generated after the spontaneous insertion of hydroquinone-tethered alkane (H(2)Q) into egg palmitoyl-oleoyl phosphatidylcholine (egg-POPC), followed by subsequent fusion to a siloxane-terminated self-assembled monolayer (SAM) on gold. An advantage of the H(2)Q system is that it can be electrochemically oxidized to the corresponding quinone (Q), followed by rapid chemoselective conjugation with oxyamine-functionalized (RONH(2)) ligands. The oxime product is also electroactive, and the reaction can be monitored and the amount of ligand bound can be quantified by electrochemistry. The bilayers were characterized by electrochemistry, fluorescence microscopy, and ellipsometry and were determined to be fluid by fluorescence recovery after photobleaching (FRAP). This strategy provides a synergistic method to pattern and present a number of ligands or biomolecules from the bilayer surface for the evaluation of enzyme or protein binding to biomembranes.
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Affiliation(s)
- Debjit Dutta
- Department of Chemistry and the Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA
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16
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Kurita R, Arai K, Nakamoto K, Kato D, Niwa O. Development of electrogenerated chemiluminescence-based enzyme linked immunosorbent assay for sub-pM detection. Anal Chem 2010; 82:1692-7. [PMID: 20143889 DOI: 10.1021/ac902045y] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper reports the development and characterization of a highly sensitive enzyme linked immunosorbent assay realized by the electrogenerated chemiluminescence (ECL) detection of a thiol monolayer formed by an enzyme labeled antibody. We used two monoclonal anti tumor necrosis factor-alpha (TNF-alpha) antibodies for a sandwich immunoassay. One was a capture antibody, and the other was a detection antibody labeled with an enzyme via an avidin-biotin interaction. Acetylcholinesterase was used as the labeling enzyme to convert acetylthiocholine to thiocholine. Then the thiocholine was collected on a gold electrode surface by gold-thiol binding. A bright and distinctive emission was observed at 1150 mV (vs Ag-AgCl) on the gold electrode with a thiocholine monolayer as a coreactant in the presence of tris(2,2'-bipyridyl)ruthenium complex. This method can greatly enhance the immunoassay signal since a large number of coreactant molecules can be generated by the enzymatic reaction, which is advantageous compared with a previously reported ECL based immunoassay that directly labels the detection antibody with a coreactant or luminophore. In addition, a surface accumulated coreactant is superior to the previously reported coreactant system in a bulk solution, because ECL emission occurs only very close to an electrode surface. As a result, high sensitivity and a low detection limit of 0.2 pM (3.4 pg/mL) TNF-alpha were achieved with excellent reproducibility by optimizing the conditions for the immuno-reaction, thiocholine accumulation, and ECL generation.
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Affiliation(s)
- Ryoji Kurita
- National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan 305-8566.
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Barriet D, Chinwangso P, Lee TR. Can cyclopropyl-terminated self-assembled monolayers on gold be used to mimic the surface of polyethylene? ACS APPLIED MATERIALS & INTERFACES 2010; 2:1254-1265. [PMID: 20423144 DOI: 10.1021/am1001585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This paper describes the formation of a new series of monolayer films generated by the self-assembly of omega-cyclopropylalkanethiols, CyPr(CH(2))(n)SH (n = 9-13), onto the surface of gold. Procedures used to prepare the omega-cyclopropylalkanethiol adsorbates are also reported. Methyl-, vinyl-, and isopropyl-terminated self-assembled monolayers (SAMs) were also prepared and used as reference films to evaluate the structure and properties of the new cyclopropyl-terminated films. Ellipsometry and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) were used to examine the structure of the SAMs. A small but systematically lower thickness of the new films compared to that of analogous methyl-terminated SAMs was observed. Also, the orientation of the ring with respect to the surface normal was observed to vary systematically with the number of methylene groups in the adsorbate backbone (i.e., odd vs even chain lengths). Measurements of wettability by contact angle goniometry also revealed a small but reproducible "odd-even" effect for all contacting liquids used, except hexadecane, which almost completely wet the surfaces (theta(a) = 10-13 degrees ). When compared to the wettability data obtained from methyl- and isopropyl-terminated SAMs, the wettability data obtained from the cyclopropyl-terminated SAMs suggest that these films offer an increased density of atomic contacts per unit area across the surface, and thus enhanced attractive interactions with contacting liquids. Comparison of the wettabilities of vinyl-terminated and cyclopropyl-terminated films is complicated by dipole-induced dipole interactions and/or pi-pi interactions between the surfaces and the probe liquids. Furthermore, the significantly similar wettabilities of the cyclopropyl-terminated SAMs and the surface of polyethylene suggests that these SAMs (and perhaps other SAMs with judiciously designed tailgroups) can be used to mimic the interfacial properties of polymeric materials without complications arising from surface reconstruction.
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Affiliation(s)
- David Barriet
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
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Pulsipher A, Yousaf MN. Tandem surface microfluidic lithography and activation to generate patch pattern biospecific ligand and cell arrays. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:4130-4135. [PMID: 19839568 DOI: 10.1021/la903297d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report a rapid, inexpensive, and flexible methodology that combines microfluidic lithography and oxidative activation to pattern and chemically alter selective regions of SAMs on gold for subsequent chemoselective ligand immobilization. We demonstrate that PCC, a mild oxidant, can be used to convert hydroxyl-terminated SAMs to aldehydes and decorated with a variety of oxyamine-containing molecules. This strategy is compatible with cell culture and was employed to create a biospecific ligand platform for peptide-mediated, cell adhesion arrays. By using a number of different ligands and characterization tools, we showed that the generation of both cell patterning and ligand microarray patterning can be achieved. SAM formation, activation, ligand immobilization, and biospecific cell patterning are characterized by contact angle, cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS) (Supporting Information), scanning electron microscopy (SEM), and fluorescence microscopy.
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Affiliation(s)
- Abigail Pulsipher
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA
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Self-Assembled Monolayers as Dynamic Model Substrates for Cell Biology. BIOACTIVE SURFACES 2010. [DOI: 10.1007/12_2010_87] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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20
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Robertus J, Browne WR, Feringa BL. Dynamic control over cell adhesive properties using molecular-based surface engineering strategies. Chem Soc Rev 2010; 39:354-78. [DOI: 10.1039/b906608j] [Citation(s) in RCA: 194] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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21
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Abstract
An approach for complex cell patterning, using laser printing, is described allowing essentially any cellular image or pattern to be rapidly fabricated.
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Affiliation(s)
- Albert Liberski
- EaStCHEM, School of Chemistry, King's Building, West Mains Road, University of Edinburgh, Edinburgh, UK EH9 3JJ
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22
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Toh CR, Fraterman TA, Walker DA, Bailey RC. Direct biophotolithographic method for generating substrates with multiple overlapping biomolecular patterns and gradients. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8894-8. [PMID: 19601565 PMCID: PMC3960942 DOI: 10.1021/la9019537] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We describe an approach to generate multicomponent surface-immobilized patterns and gradients on the basis of the photochemically controlled covalent coupling of solution-phase biomolecules to benzophenone-modified substrates. Gradients were simply achieved by continuously varying the exposure to nondamaging UV light across the surface with the gradient profile controlled by biomolecule concentration and the spatial and temporal illumination of the surface. Sequential exposure of the same surface in the presence of different biomolecules resulted in overlapping patterns and gradients of proteins and carbohydrates. Finally, we preliminarily demonstrate that the resulting surfaces are suitable for generating model substrates to probe cell-substrate interactions.
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Pulsipher A, Westcott NP, Luo W, Yousaf MN. Rapid in Situ Generation of Two Patterned Chemoselective Surface Chemistries from a Single Hydroxy-Terminated Surface Using Controlled Microfluidic Oxidation. J Am Chem Soc 2009; 131:7626-32. [DOI: 10.1021/ja809380e] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Abigail Pulsipher
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290
| | - Nathan P. Westcott
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290
| | - Wei Luo
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290
| | - Muhammad N. Yousaf
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290
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24
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Kim YK, Ryoo SR, Kwack SJ, Min DH. Mass Spectrometry Assisted Lithography for the Patterning of Cell Adhesion Ligands on Self-Assembled Monolayers. Angew Chem Int Ed Engl 2009; 48:3507-11. [DOI: 10.1002/anie.200806098] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kim YK, Ryoo SR, Kwack SJ, Min DH. Mass Spectrometry Assisted Lithography for the Patterning of Cell Adhesion Ligands on Self-Assembled Monolayers. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200806098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Harper JC, Polsky R, Wheeler DR, Lopez DM, Arango DC, Brozik SM. A multifunctional thin film Au electrode surface formed by consecutive electrochemical reduction of aryl diazonium salts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3282-3288. [PMID: 19437729 DOI: 10.1021/la803215z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A multifunctional thin film surface capable of immobilizing two diverse molecules on a single gold electrode was prepared by consecutive electrodeposition of nitrophenyl and phenylboronic acid pinacol ester (PBA-PE) diazonium salts. Activation of the stacked film toward binding platinum nanoparticles (PtNPs) and yeast cells occurred via chemical deprotection of the pinacol ester followed by electroreduction of nitro to amino groups. FTIR spectral analysis was used to study and verify film composition at each stage of preparation. The affect of electrodeposition protocol over the thickness of the nitrophenyl and PBA-PE layers was explored and had a profound impact on the film properties. Thicker nitrophenyl films led to diminished PBA-PE diazonium reduction currents during assembly and decreased phenylboronic acid (PBA) layer thickness while allowing for higher PtNP loading and catalytic currents from PtNP-mediated peroxide reduction. Multilayer PBA films could be formed over the nitrophenyl film; however, only submonlayer PBA films permitted access to the underlying layer. The sequence of functional group activation toward binding was also shown to be significant, as perchlorate used to remove pinacol ester also converted aminophenyl groups accessible to the solution to nitrophenyl groups, preventing electrostatic PtNP binding. Finally, SEM images show PtNPs immobilized in close proximity (nanometers) to captured yeast cells on the PBA-aminophenyl-Au film. Such multibinding functionality films that maintain conductivity for subsequent electrochemical measurements hold promise for the development of electrochemical and/or optical platforms for fundamental cell studies, genomic and proteomic analysis, and biosensing.
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Affiliation(s)
- Jason C Harper
- Biosensors & Nanomaterials, Sandia National Laboratories, PO Box 5800, MS-0892, Albuquerque, New Mexico 87185, USA
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PEG hydrogels for the controlled release of biomolecules in regenerative medicine. Pharm Res 2008; 26:631-43. [PMID: 19089601 DOI: 10.1007/s11095-008-9801-2] [Citation(s) in RCA: 672] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 12/01/2008] [Indexed: 02/07/2023]
Abstract
Polyethylene glycol (PEG) hydrogels are widely used in a variety of biomedical applications, including matrices for controlled release of biomolecules and scaffolds for regenerative medicine. The design, fabrication, and characterization of PEG hydrogels rely on the understanding of fundamental gelation kinetics as well as the purpose of the application. This review article will focus on different polymerization mechanisms of PEG-based hydrogels and the importance of these biocompatible hydrogels in regenerative medicine applications. Furthermore, the design criteria that are important in maintaining the availability and stability of the biomolecules as well as the mechanisms for loading of biomolecules within PEG hydrogels will also be discussed. Finally, we overview and provide a perspective on some of the emerging novel design and applications of PEG hydrogel systems, including the spatiotemporal-controlled delivery of biomolecules, hybrid hydrogels, and PEG hydrogels designed for controlled stem cell differentiation.
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Luo W, Westcott NP, Pulsipher A, Yousaf MN. Renewable and optically transparent electroactive indium tin oxide surfaces for chemoselective ligand immobilization and biospecific cell adhesion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13096-13101. [PMID: 18928305 DOI: 10.1021/la802775v] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In this report, we show the successful transfer of a sophisticated electroactive immobilization and release strategy to an indium tin oxide (ITO) surface to generate (1) optically transparent, robust, and renewable surfaces, (2) inert surfaces that resist nonspecific protein adsorption and cell attachment, and (3) tailored biospecific surfaces for live-cell high-resolution fluorescence microscopy of cell culture. By comparing the surface chemistry properties on both ITO and gold surfaces, we demonstrate the ITO surfaces are superior to gold as a renewable surface, in robustness (durability), and as an optically transparent material for live-cell fluorescence microscopy studies of cell behavior. These advantages will make ITO surfaces a desired platform for numerous biosensor and microarray applications and as model substrates for various cell biological studies.
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Affiliation(s)
- Wei Luo
- Department of Chemistry and Carolina Center for Genome Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA
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Lamb BM, Westcott NP, Yousaf MN. Microfluidic Lithography to Create Dynamic Gradient SAM Surfaces for Spatio-temporal Control of Directed Cell Migration. Chembiochem 2008; 9:2628-32. [DOI: 10.1002/cbic.200800473] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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