1
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Duleba D, Denuga S, Johnson RP. Reproducibility and stability of silane layers in nanoconfined electrochemical systems. Phys Chem Chem Phys 2024; 26:15452-15460. [PMID: 38747528 DOI: 10.1039/d4cp01181c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Organosilanes are commonly utilized to attach bioreceptors to oxide surfaces. The deposition of such silane layers is especially challenging in nanoscale or nanoconfined devices, such as in nanopipettes, since rinsing off loosely bound silanes may not be possible due to geometric constrictions and because the thickness of multilayered silanes can cover or block nanoscale features. Furthermore, in electrochemical devices, the silane layers experience additional perturbations, such as electric migration and electroosmotic force. Despite its importance, there appears to be no consensus in the current literature on the optimal methodology for nanopipette silanization, with significant variations in reported conditions. Herein, we systematically investigate the reproducibility and stability of liquid- and vapor-phase deposited silane layers inside nanopipettes. Electrochemical monitoring of the changing internal silanized surface reveals that vapor-deposited APTES generates surface modifications with the highest reproducibility, while vapor-deposited APTMS generates surface modifications of the highest stability over a 24-hour time period. Practical issues of silanizing nanoconfined systems are highlighted, and the importance of carefully chosen silanization conditions to yield stable and reproducible monolayers is emphasized as an underappreciated aspect in the development of novel nanoscale systems.
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Affiliation(s)
- Dominik Duleba
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Shekemi Denuga
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Robert P Johnson
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
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2
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Landoulsi J. Surface (bio)-functionalization of metallic materials: How to cope with real interfaces? Adv Colloid Interface Sci 2024; 325:103054. [PMID: 38359674 DOI: 10.1016/j.cis.2023.103054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 02/17/2024]
Abstract
Metallic materials are an important class of biomaterials used in various medical devices, owing to a suitable combination of their mechanical properties. The (bio)-functionalization of their surfaces is frequently performed for biocompatibility requirements, as it offers a powerful way to control their interaction with biological systems. This is particularly important when physicochemical processes and biological events, mainly involving proteins and cells, are initiated at the host-material interface. This review addresses the state of "real interfaces" in the context of (bio)-functionalization of metallic materials, and the necessity to cope with it to avoid frequent improper evaluation of the procedure used. This issue is, indeed, well-recognized but often neglected and emerges from three main issues: (i) ubiquity of surface contamination with organic compounds, (ii) reactivity of metallic surfaces in biological medium, and (iii) discrepancy in (bio)-functionalization procedures between expectations and reality. These disturb the assessment of the strategies adopted for surface modifications and limit the possibilities to provide guidelines for their improvements. For this purpose, X-ray photoelectrons spectroscopy (XPS) comes to the rescue. Based on significant progresses made in methodological developments, and through a large amount of data compiled to generate statistically meaningful information, and to insure selectivity, precision and accuracy, the state of "real interfaces" is explored in depth, while looking after the two main constituents: (i) the bio-organic adlayer, in which the discrimination between the compounds of interest (anchoring molecules, coupling agents, proteins, etc) and organic contaminants can be made, and (ii) the metallic surface, which undergoes dynamic processes due to their reactivity. Moreover, through one of the widespread (bio)-functionalization strategy, given as a case study, a particular attention is devoted to describe the state of the interface at different stages (composition, depth distribution of contaminants and (bio)compounds of interest) and the mode of protein retention. It is highlighted, in particular, that the occurrence or improvement of bioactivity does not demonstrate that the chemical schemes worked in reality. These aspects are particularly essential to make progress on the way to choose the suitable (bio)-functionalization strategy and to provide guidelines to improve its efficiency.
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Affiliation(s)
- Jessem Landoulsi
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface, 4 place Jussieu, F-75005 Paris, France; Laboratoire de Biomécanique & Bioingénierie, CNRS, Université de Technologie de Compiègne, 20529 F-60205 Compiègne Cedex, France.
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3
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Millot Y, Hervier A, Ayari J, Hmili N, Blanchard J, Boujday S. Revisiting Alkoxysilane Assembly on Silica Surfaces: Grafting versus Homo-Condensation in Solution. J Am Chem Soc 2023; 145:6671-6681. [PMID: 36926855 DOI: 10.1021/jacs.2c11390] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Silica surface functionalization is often done through the condensation of functional silanes on silanols, silica surfaces' terminal groups. APTES, aminopropyltriethoxysilane, is widely used due to its assumed high reactivity with silanols, kinetically promoted by the catalytic action of the terminal amine function. Here, we revisit, based on a quantitative analysis by solid-state 29Si NMR, the assembly of this silane on silica surfaces to investigate whether its presence results from grafting, i.e., hetero-condensation with silanol groups or from homo-condensation of silane molecules in solution leading to polycondensates physisorbed on silica. We investigate the interaction of APTES with a crystalline layered silicate, ilerite, and with amorphous nonporous silica. We also studied a second silane, cyanopropyltrichlorosilane (CPTCS), terminated with a nitrile group. Our results undoubtedly prove that while CPTCS is grafted on the silica surface, the presence of APTES on silica and silicate materials is only marginally associated with silanol consumption. The analysis of the signal related to silicon atoms from silanes (Tn species) and those from silica (Qn species) allowed for the accurate estimation of the extent of homo-condensation vs grafting based on the ratio of T-O-T/Q-O-T siloxane bridges. These findings deeply question the well-established certainties on APTES assembly on silica that should no longer be seen as grafting of alkoxysilane by hetero-condensation with silanol groups but more accurately as a homo-condensed network of silanes, predominantly physisorbed on the surface but including some sparse anchoring points to the surface involving less than 6% of the overall silanol groups.
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Affiliation(s)
- Yannick Millot
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 place Jussieu, F-75005 Paris, France
| | - Antoine Hervier
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 place Jussieu, F-75005 Paris, France
| | - Jihed Ayari
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 place Jussieu, F-75005 Paris, France
| | - Naoures Hmili
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 place Jussieu, F-75005 Paris, France
| | - Juliette Blanchard
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 place Jussieu, F-75005 Paris, France
| | - Souhir Boujday
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 place Jussieu, F-75005 Paris, France
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4
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Kasinathan P, Lang C, Gaigneaux EM, Jonas AM, Fernandes AE. Influence of Site Pairing in Hydrophobic Silica-Supported Sulfonic Acid Bifunctional Catalysts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13743-13751. [PMID: 33170709 DOI: 10.1021/acs.langmuir.0c01759] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Imparting hydrophobicity to solid acid catalysts is critical to regulating their performances by allowing the creation of a less polar environment and improved partitioning of the reactants. Here we present different approaches for the preparation of silica-based catalysts comprising sulfonic acid (-SO3H) sites and hydrophobic decyl (-C10) chains by either simultaneous or sequential postfunctionalization of an azide-functionalized mesoporous silica platform. This set of hybrid bifunctional catalysts is compared in the model esterification of octanol with acetic acid, and the influence of the preparation methods together with the resulting site spatial distribution is discussed. In parallel, we show that pairing the two functional groups affords a maximum synergistic effect compared to more traditional mixed catalysts with random distributions of acid and hydrophobic functions.
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Affiliation(s)
- Palraj Kasinathan
- Institute of Condensed Matter and Nanosciences, Bio- and Soft Matter, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Charlotte Lang
- Institute of Condensed Matter and Nanosciences, Bio- and Soft Matter, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Eric M Gaigneaux
- Institute of Condensed Matter and Nanosciences, Bio- and Soft Matter, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Alain M Jonas
- Institute of Condensed Matter and Nanosciences, Bio- and Soft Matter, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Antony E Fernandes
- Institute of Condensed Matter and Nanosciences, Bio- and Soft Matter, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
- Certech, Rue Jules Bordet 45, 7180 Seneffe, Belgium
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5
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Quantin P, Colaço E, El Kirat K, Egles C, Ficheux H, Landoulsi J. Layer-by-Layer Assembly of Nanosized Membrane Fractions for the Assessment of Cytochrome P450 Xenobiotic Metabolism. ACS OMEGA 2018; 3:12535-12544. [PMID: 31457987 PMCID: PMC6644547 DOI: 10.1021/acsomega.8b01738] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 09/19/2018] [Indexed: 06/01/2023]
Abstract
Herein, we report the use of sequential layer-by-layer (LbL) assembly to design nanostructured films made of recombinant bacterial membrane fractions (MF), which overexpress cytochrome P450 (CYP) and cytochrome P450 reductase. The ability to incorporate MF in LbL multilayered films is demonstrated by an in situ quartz crystal microbalance with dissipation monitoring using poly-l-lysine or poly-l-ornithine as a polycation. Results show that MF preserve a remarkable CYP1A2 catalytic property in the adsorbed phase. Moreover, atomic force microscopy images reveal that MF mostly adopt a flattened conformation in the adsorbed phase with an extensive tendency to aggregate within the multilayered films, which is more pronounced when increasing the number of bilayers. Interestingly, this behavior seems to enhance the ability of embedded MF to remain active after repeated uses. The proposed strategy constitutes a practical alternative for the immobilization of active CYP enzymes. Besides their fundamental interest, MF-based multilayers are useful nano-objects for the creation of new biomimetic reactors for the assessment of xenobiotic metabolism.
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Affiliation(s)
- Paul Quantin
- Département
de Toxicologie, THOR Personal Care, 147 Rue Irene Joliot Curie, 60610 La Croix-Saint-Ouen, France
- Université
de Technologie de Compiègne, Laboratoire de Biomécanique & Bioingénierie,
CNRS, UMR 7338, Rue Personne
de Roberval, 60200 Compiègne, France
| | - Elodie Colaço
- Université
de Technologie de Compiègne, Laboratoire de Biomécanique & Bioingénierie,
CNRS, UMR 7338, Rue Personne
de Roberval, 60200 Compiègne, France
| | - Karim El Kirat
- Université
de Technologie de Compiègne, Laboratoire de Biomécanique & Bioingénierie,
CNRS, UMR 7338, Rue Personne
de Roberval, 60200 Compiègne, France
| | - Christophe Egles
- Université
de Technologie de Compiègne, Laboratoire de Biomécanique & Bioingénierie,
CNRS, UMR 7338, Rue Personne
de Roberval, 60200 Compiègne, France
| | - Hervé Ficheux
- Département
de Toxicologie, THOR Personal Care, 147 Rue Irene Joliot Curie, 60610 La Croix-Saint-Ouen, France
| | - Jessem Landoulsi
- Université
de Technologie de Compiègne, Laboratoire de Biomécanique & Bioingénierie,
CNRS, UMR 7338, Rue Personne
de Roberval, 60200 Compiègne, France
- Sorbonne
Université, CNRS - UMR 7197, Laboratoire de Réactivité
de Surface, 4 Place Jussieu, F-75005 Paris, France
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6
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Qin G, Yam CM, Kumar A, Lopez-Romero JM, Li S, Huynh T, Li Y, Yang B, Contreras-Caceres R, Cai C. Preparation, characterization, and protein-resistance of films derived from a series of α-oligo(ethylene glycol)-ω-alkenes on H–Si(111) surfaces. RSC Adv 2017. [DOI: 10.1039/c6ra28497c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Films on Si(111) were prepared by photo-activated grafting of CH2CH(CH2)m(OCH2CH2)nOCH3 (m = 8, 9; n = 3–7) by using different vacuum conditions. High vacuum produced a higher thickness (40 Å) and <0.8% fibrinogen adsorption (C10EG7). Films were stable even after 28 days.
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Affiliation(s)
- Guoting Qin
- College of Optometry
- University of Houston
- Houston
- USA
| | - Chi Ming Yam
- Department of Chemistry & Center for Materials Chemistry
- University of Houston
- Houston
- USA
| | - Amit Kumar
- Department of Chemistry & Center for Materials Chemistry
- University of Houston
- Houston
- USA
| | - J. Manuel Lopez-Romero
- Departamento de Química Orgánica
- Facultad de Ciencias
- Universidad de Málaga
- 29071 Málaga
- Spain
| | - Sha Li
- Department of Chemistry & Center for Materials Chemistry
- University of Houston
- Houston
- USA
| | - Toan Huynh
- Department of Chemistry & Center for Materials Chemistry
- University of Houston
- Houston
- USA
| | - Yan Li
- Department of Chemistry & Center for Materials Chemistry
- University of Houston
- Houston
- USA
| | - Bin Yang
- Department of Chemistry & Center for Materials Chemistry
- University of Houston
- Houston
- USA
| | | | - Chengzhi Cai
- Department of Chemistry & Center for Materials Chemistry
- University of Houston
- Houston
- USA
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7
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Ataman NC, Klok HA. Degrafting of Poly(poly(ethylene glycol) methacrylate) Brushes from Planar and Spherical Silicon Substrates. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01445] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Nariye Cavusoglu Ataman
- Institut des Matériaux
et Institut des Sciences et Ingénierie Chimiques, Laboratoire
des Polyméres, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
| | - Harm-Anton Klok
- Institut des Matériaux
et Institut des Sciences et Ingénierie Chimiques, Laboratoire
des Polyméres, École Polytechnique Fédérale de Lausanne (EPFL), Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
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8
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Yang Y, Wikieł AJ, Dall'Agnol LT, Eloy P, Genet MJ, Moura JJG, Sand W, Dupont-Gillain CC, Rouxhet PG. Proteins dominate in the surface layers formed on materials exposed to extracellular polymeric substances from bacterial cultures. BIOFOULING 2016; 32:95-108. [PMID: 26769222 DOI: 10.1080/08927014.2015.1114609] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The chemical compositions of the surface conditioning layers formed by different types of solutions (from isolated EPS to whole culture media), involving different bacterial strains relevant for biocorrosion were compared, as they may influence the initial step in biofilm formation. Different substrata (polystyrene, glass, steel) were conditioned and analyzed by X-ray photoelectron spectroscopy. Peak decomposition and assignment were validated by correlations between independent spectral data and the ubiquitous presence of organic contaminants on inorganic substrata was taken into account. Proteins or peptides were found to be a major constituent of all conditioning layers and polysaccharides were not present in appreciable concentrations; the proportion of nitrogen which may be due to DNA was lower than 15%. There was no significant difference between the compositions of the adlayers formed from different conditioning solutions, except for the adlayers produced with tightly bound EPS extracted from D. alaskensis.
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Affiliation(s)
- Yi Yang
- a Institute of Condensed Matter and Nanoscience (IMCN) - Bio & Soft Matter (BSMA) , Université catholique de Louvain , Louvain-la-Neuve , Belgium
| | - Agata J Wikieł
- b Biofilm Centre, Aquatische Biotechnologie , Universität Duisburg - Essen , Essen , Germany
| | - Leonardo T Dall'Agnol
- c REQUIMTE-CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , Caparica , Portugal
| | - Pierre Eloy
- a Institute of Condensed Matter and Nanoscience (IMCN) - Bio & Soft Matter (BSMA) , Université catholique de Louvain , Louvain-la-Neuve , Belgium
| | - Michel J Genet
- a Institute of Condensed Matter and Nanoscience (IMCN) - Bio & Soft Matter (BSMA) , Université catholique de Louvain , Louvain-la-Neuve , Belgium
| | - José J G Moura
- c REQUIMTE-CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , Caparica , Portugal
| | - Wolfgang Sand
- b Biofilm Centre, Aquatische Biotechnologie , Universität Duisburg - Essen , Essen , Germany
| | - Christine C Dupont-Gillain
- a Institute of Condensed Matter and Nanoscience (IMCN) - Bio & Soft Matter (BSMA) , Université catholique de Louvain , Louvain-la-Neuve , Belgium
| | - Paul G Rouxhet
- a Institute of Condensed Matter and Nanoscience (IMCN) - Bio & Soft Matter (BSMA) , Université catholique de Louvain , Louvain-la-Neuve , Belgium
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9
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A Comprehensive Study of Silanization and Co-Condensation for Straightforward Single-Step Covalent Neutral Capillary Coating. Chromatographia 2015. [DOI: 10.1007/s10337-015-2895-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Elschner T, Heinze T. Cellulose carbonates: a platform for promising biopolymer derivatives with multifunctional capabilities. Macromol Biosci 2015; 15:735-46. [PMID: 25677921 DOI: 10.1002/mabi.201400521] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/16/2015] [Indexed: 02/03/2023]
Abstract
Cellulose carbonates as a platform compound open new possibilities for the design of advanced materials based on the most important renewable resource cellulose. In the present feature, the chemistry of cellulose carbonates is discussed considering own research results adequately. After a short overview about methods for activation of polysaccharides for a conversion with nucleophilic compounds in particular with amines, details about various methods for the synthesis of polysaccharide carbonates are discussed. The main issue of the feature is the synthesis and aminolysis of cellulose carbonates with low, intermediate, and high degree of substitution and the evaluation of this chemistry with respect to specific challenges. Functional cellulose carbamates, obtained from cellulose phenyl carbonate by aminolysis, show the potential use of this class of celluloses. Immunoassays and zwitterionic polymers are included as representative examples regarding properties and application of the new cellulose-based products.
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Affiliation(s)
- Thomas Elschner
- Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743, Jena, Germany
| | - Thomas Heinze
- Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstraße 10, 07743, Jena, Germany.
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11
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Huebner M, Ben Haddada M, Méthivier C, Niessner R, Knopp D, Boujday S. Layer-by-layer generation of PEG-based regenerable immunosensing surfaces for small-sized analytes. Biosens Bioelectron 2014; 67:334-41. [PMID: 25201037 DOI: 10.1016/j.bios.2014.08.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/18/2014] [Accepted: 08/20/2014] [Indexed: 12/27/2022]
Abstract
Small molecules (haptens) like pharmaceuticals or peptides can serve as targets for antibody binding in competitive immunoassay-based flow-through assays. In this work, a strategy for preparing polyethylene glycol (PEG) coatings for subsequent hapten immobilization on glass-type silica surfaces is presented and characterized in detail. Two substrates bearing terminal silanol groups were utilized, a glass slide and a silicon wafer. First, surfaces were thoroughly cleaned and pretreated to generate additional silanol groups. Then, a silane layer with terminal epoxy groups was created using 3-glycidyloxypropyltrimethoxysilane (GOPTS). Epoxy groups were used to bind a layer of diamino-poly(ethylene glycol) (DAPEG) with terminal amino groups. Finally, the low molecular weight compound diclofenac was bound to the surface to be used as model ligand for competitive biosensing of haptens. The elementary steps were characterized using atomic force microscopy (AFM), water contact angle measurement, grazing-angle attenuated total reflection (GA-ATR) FT-IR spectroscopy, and X-ray photoelectron spectroscopy (XPS). The data collected using these techniques have confirmed the successive grafting of the molecular species, evidencing, that homogeneous monolayers were created on the silica surfaces and validated the proposed mechanism of functionalization. The resulting surfaces were used to investigate polyclonal anti-diclofenac antibodies recognition and reversibility using quartz crystal microbalance with dissipation (QCM-D) measurements or an automated flow-through immunoassay with chemiluminescence (CL) read-out. For both techniques, recognition and reversibility of the antibody binding were observed. The stability of sensors over time was also assessed and no decrease in CL response was observed upon 14 days in aqueous solution. The herein presented strategy for surface functionalization can be used in the future as reproducible and reusable universal platform for hapten biosensors.
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Affiliation(s)
- Maria Huebner
- Chair for Analytical Chemistry and Institute of Hydrochemistry, Technische Universität München, Marchioninistr. 17, Munich, Germany
| | - Maroua Ben Haddada
- Sorbonne Universités, UPMC Univ Paris 6, UMR CNRS 7197, Laboratoire de Réactivité de Surface, F75005 Paris, France; CNRS, UMR 7197, Laboratoire de Réactivité de Surface, F75005 Paris, France
| | - Christophe Méthivier
- Sorbonne Universités, UPMC Univ Paris 6, UMR CNRS 7197, Laboratoire de Réactivité de Surface, F75005 Paris, France; CNRS, UMR 7197, Laboratoire de Réactivité de Surface, F75005 Paris, France
| | - Reinhard Niessner
- Chair for Analytical Chemistry and Institute of Hydrochemistry, Technische Universität München, Marchioninistr. 17, Munich, Germany
| | - Dietmar Knopp
- Chair for Analytical Chemistry and Institute of Hydrochemistry, Technische Universität München, Marchioninistr. 17, Munich, Germany.
| | - Souhir Boujday
- Sorbonne Universités, UPMC Univ Paris 6, UMR CNRS 7197, Laboratoire de Réactivité de Surface, F75005 Paris, France; CNRS, UMR 7197, Laboratoire de Réactivité de Surface, F75005 Paris, France.
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12
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Elschner T, Scholz F, Miethe P, Heinze T. Rapid Flow Through Immunoassay for CRP Determination Based on Polyethylene Filters Modified withω-Aminocellulose Carbamate. Macromol Biosci 2014; 14:1539-46. [DOI: 10.1002/mabi.201400179] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 06/13/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Thomas Elschner
- Center of Excellence for Polysaccharide Research; Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena; Humboldtstraße 10 D-07743 Jena Germany
| | - Friedrich Scholz
- Center of Excellence for Polysaccharide Research; Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena; Humboldtstraße 10 D-07743 Jena Germany
- Senova Gesellschaft für Biowissenschaft und Technik mbH; Industriestraße 8 D-99427 Weimar Germany
| | - Peter Miethe
- fzmb GmbH, Forschungszentrum für Medizintechnik und Biotechnologie; Geranienweg 7 D-99947 Bad Langensalza Germany
| | - Thomas Heinze
- Center of Excellence for Polysaccharide Research; Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena; Humboldtstraße 10 D-07743 Jena Germany
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13
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Aissaoui N, Bergaoui L, Boujday S, Lambert JF, Méthivier C, Landoulsi J. Enzyme immobilization on silane-modified surface through short linkers: fate of interfacial phases and impact on catalytic activity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4066-4077. [PMID: 24635492 DOI: 10.1021/la404935q] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigated the mechanism of enzyme immobilization on silanized surfaces through coupling agents (cross-linkers) in order to understand the role of these molecules on interfacial processes and their effect on catalytic activity. To this end, we used a model multimeric enzyme (G6PDH) and several cross-linking molecules with different chemical properties, including the nature of the end-group (-NCO, -NCS, -CHO), the connecting chain (aliphatic vs aromatic), and geometrical constraints (meta vs para-disubstituted aromatics). There did not seem to be radical differences in the mechanism of enzyme adsorption according to the linker used as judged from QCM-D, except that in the case of DIC (1,4-phenylene diisocyanate) the adsorption occurred more rapidly. In contrast, the nature of the cross-linker exerted a strong influence on the amount of enzyme immobilized as estimated from XPS, and more unexpectedly on the stability of the underlying silane layer. DIC, PDC (1,4-phenylene diisothiocyanate), or GA (glutaraldehyde) allowed successful enzyme immobilization. When the geometry of the linker was changed from 1,4-phenylene diisothiocyanate to 1,3-phenylene diisothiocyanate (MDC), the silane layer was subjected to degradation, upon enzyme adsorption, and the amount of immobilized molecules was significantly lowered. TE (terephtalaldehyde) and direct enzyme deposition without cross-linker were similar to MDC. The organization of immobilized enzymes also depended on the immobilization procedure, as different degrees of aggregation were observed by AFM. A correlation between the size of the aggregates and the catalytic properties of the enzyme was established, suggesting that aggregation may enhance the thermostability of the multimeric enzyme, probably through a compaction of the 3D structure.
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Affiliation(s)
- Nesrine Aissaoui
- Sorbonne Universités, UPMC Univ Paris 06 , F-75005, Paris, France
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14
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Yang Y, Poleunis C, Románszki L, Telegdi J, Dupont-Gillain CC. Adsorption of a PEO-PPO-PEO triblock copolymer on metal oxide surfaces with a view to reducing protein adsorption and further biofouling. BIOFOULING 2013; 29:1123-1137. [PMID: 24050779 DOI: 10.1080/08927014.2013.830109] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Abstract Biomolecule adsorption is the first stage of biofouling. The aim of this work was to reduce the adsorption of proteins on stainless steel (SS) and titanium surfaces by modifying them with a poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO)-PEO triblock copolymer. Anchoring of the central PPO block of the copolymer is known to be favoured by hydrophobic interaction with the substratum. Therefore, the surfaces of metal oxides were first modified by self-assembly of octadecylphosphonic acid. PEO-PPO-PEO preadsorbed on the hydrophobized surfaces of titanium or SS was shown to prevent the adsorption of bovine serum albumin (BSA), fibrinogen and cytochrome C, as monitored by quartz crystal microbalance (QCM). Moreover, X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry were used to characterize the surfaces of the SS and titanium after competitive adsorption of PEO-PPO-PEO and BSA. The results show that the adsorption of BSA is well prevented on hydrophobized surfaces, in contrast to the surfaces of native metal oxides.
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Affiliation(s)
- Y Yang
- a Surfaces Group (SURF), Bio- and Soft Matter (BSMA) , Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain , Louvain-la-Neuve , Belgium
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15
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Chen J, Wang J, Qi P, Li X, Ma B, Chen Z, Li Q, Zhao Y, Xiong K, Maitz MF, Huang N. Biocompatibility studies of poly(ethylene glycol)–modified titanium for cardiovascular devices. J BIOACT COMPAT POL 2012. [DOI: 10.1177/0883911512461108] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The rapid protein adsorption on a material surface causes blood coagulation, platelet activation, and complement system activation, which poses a risk for failure of cardiovascular devices. In this study, a chemically hydroxylated titanium surface was aminosilanized and covalently grafted with poly(ethylene glycol). The reaction conditions on the grafted quantity were studied by the respective amine and carboxyl densities. The blood compatibility of the PEGylated surfaces with different poly(ethylene glycol) densities and chain lengths was evaluated; the PEGylated surfaces with higher grafted density and longer chain length had less fibrinogen adsorption, less fibrinogen γ-chain exposed, less adherent platelets, and lower activation of the adherent platelets. In addition to the influence on blood, the longer chain PEGylated surfaces resisted, not only smooth muscle cell attachment and proliferation, but also macrophage attachment and death. This method is a good candidate for improving cardiovascular implant surfaces.
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Affiliation(s)
- Jialong Chen
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
- College of Stomatology, Anhui Medical University, Hefei, China
| | - Juan Wang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
| | - Pengkai Qi
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
| | - Xin Li
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
| | - Baolong Ma
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, China
| | - Zhuoyue Chen
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
| | - Quanli Li
- College of Stomatology, Anhui Medical University, Hefei, China
| | - Yuancong Zhao
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
| | - Kaiqin Xiong
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
| | - Manfred F Maitz
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
- Max Bergmann Center of Biomaterials Dresden, Leibniz Institute of Polymer Research Dresden, Dresden, Germany
| | - Nan Huang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, China
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16
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Zhong M, Lee CY, Croushore CA, Sweedler JV. Label-free quantitation of peptide release from neurons in a microfluidic device with mass spectrometry imaging. LAB ON A CHIP 2012; 12:2037-45. [PMID: 22508372 PMCID: PMC3558029 DOI: 10.1039/c2lc21085a] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Microfluidic technology allows the manipulation of mass-limited samples and when used with cultured cells, enables control of the extracellular microenvironment, making it well suited for studying neurons and their response to environmental perturbations. While matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) provides for off-line coupling to microfluidic devices for characterizing small-volume extracellular releasates, performing quantitative studies with MALDI is challenging. Here we describe a label-free absolute quantitation approach for microfluidic devices. We optimize device fabrication to prevent analyte losses before measurement and then incorporate a substrate that collects the analytes as they flow through a collection channel. Following collection, the channel is interrogated using MS imaging. Rather than quantifying the sample present via MS peak height, the length of the channel containing appreciable analyte signal is used as a measure of analyte amount. A linear relationship between peptide amount and band length is suggested by modeling the adsorption process and this relationship is validated using two neuropeptides, acidic peptide (AP) and α-bag cell peptide [1-9] (αBCP). The variance of length measurement, defined as the ratio of standard error to mean value, is as low as 3% between devices. The limit of detection (LOD) of our system is 600 fmol for AP and 400 fmol for αBCP. Using appropriate calibrations, we determined that an individual Aplysia bag cell neuron secretes 0.15 ± 0.03 pmol of AP and 0.13 ± 0.06 pmol of αBCP after being stimulated with elevated KCl. This quantitation approach is robust, does not require labeling, and is well suited for miniaturized off-line characterization from microfluidic devices.
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Affiliation(s)
| | | | | | - Jonathan V. Sweedler
- Corresponding Author: Jonathan V. Sweedler, , Phone: 217-244-7359, Fax: 217-265-6290
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17
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Dekeyser CM, Buron CC, Derclaye SR, Jonas AM, Marchand-Brynaert J, Rouxhet PG. Degradation of bare and silanized silicon wafer surfaces by constituents of biological fluids. J Colloid Interface Sci 2012; 378:77-82. [PMID: 22560491 DOI: 10.1016/j.jcis.2012.04.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 04/10/2012] [Accepted: 04/11/2012] [Indexed: 11/29/2022]
Abstract
The 24 h stability of bare silicon wafers as such or silanized with CH(3)O-(CH(2)-CH(2)-O)(n)-C(3)H(6)-trichlorosilane (n=6-9) was investigated in water, NaCl, phosphate and carbonate solutions, and in phosphate buffered saline (PBS) at 37 °C (close to biological conditions regarding temperature, high ionic strength, and pH). The resulting surfaces were analyzed using ellipsometry, X-ray Reflectometry (XRR), X-ray Photoelectron Spectroscopy (XPS), and Atomic Force Microscopy (AFM). Incubation of the silanized wafers in phosphate solution and PBS provokes a detachment of the silane layer. This is due to a hydrolysis of Si-O bonds which is favored by the action of phosphate, also responsible for a corrosion of non-silanized wafers. The surface alteration (detachment of silane layer and corrosion of the non-silanized wafer) is also important with carbonate solution, due to a higher pH (8.3). The protection of the silicon oxide layer brought by silane against the action of the salts is noticeable for phosphate but not for carbonate.
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Affiliation(s)
- C M Dekeyser
- Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Louvain-la-Neuve, Belgium
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18
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Zhang J, Lang HP, Yoshikawa G, Gerber C. Optimization of DNA hybridization efficiency by pH-driven nanomechanical bending. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:6494-6501. [PMID: 22439593 DOI: 10.1021/la205066h] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The accessibility and binding affinity of DNA are two key parameters affecting the hybridization efficiency in surface-based biosensor technologies. Better accessibility will result in a higher hybridization efficiency. Often, mixed ssDNA and mercaptohexanol monolayers are used to increase the hybridization efficiency and accessibility of surface-bound oligonucleotides to complementary target DNA. Here, no mercaptohexanol monolayer was used. We demonstrate by differential microcantilever deflection measurements at different pH that the hybridization efficiency peaks between pH 7.5 and 8.5. At low pH 4.5, hydration and electrostatic forces led to tensile surface stress, implying the reduced accessibility of the bound ssDNA probe for hybridization. In contrast, at high pH 8.5, the steric interaction between neighboring ssDNA strands was decreased by higher electrostatic repulsive forces, bending the microcantilever away from the gold surface to provide more space for the target DNA. Cantilever deflection scales with pH-dependent surface hybridization efficiency because of high target DNA accessibility. Hence, by changing the pH, the hybridization efficiency is adjusted.
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Affiliation(s)
- Jiayun Zhang
- Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland.
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19
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Aissaoui N, Bergaoui L, Landoulsi J, Lambert JF, Boujday S. Silane layers on silicon surfaces: mechanism of interaction, stability, and influence on protein adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:656-65. [PMID: 22107153 DOI: 10.1021/la2036778] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In this work the mechanism of (3-aminopropyl)triethoxysilane (APTES) interaction with silicon surfaces is investigated at the molecular level. We studied the influence of experimental parameters such as time, temperature, and concentration on the quality of the APTES layer in terms of chemical properties, morphology, and stability in aqueous medium. This was achieved using a highly sensitive IR mode recently developed, grazing angle attenuated total reflection (GA-ATR). This technique provides structural information on the formed APTES layer. The topography of this layer was investigated by atomic force microscopy in aqueous medium. The hydrophilicity was also studied using contact angle measurement. Combining these techniques enables discussion of the mechanism of silane grafting. Considerable differences were observed depending on the reaction temperature, room temperature or 90 °C. The data suggest the presence of two adsorption sites with different affinities on the oxidized silicon layer. This also allows the optimal parameters to be established to obtain an ordered and stable silane layer. The adsorption of proteins on the APTES layer was achieved and monitored using in situ quartz crystal microbalance with dissipation monitoring and ex situ GA-ATR analyses.
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Affiliation(s)
- Nesrine Aissaoui
- Laboratoire de Réactivité de Surface, UMR 7197, Université Pierre et Marie Curie, F75005 Paris, France
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20
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Affiliation(s)
- Paul G. Rouxhet
- Institute of Condensed Matter and Nanosciences - Bio & Soft Matter; Université Catholique de Louvain; Croix du Sud 1/L7.04.01; 1348; Louvain-la-Neuve; Belgium
| | - Michel J. Genet
- Institute of Condensed Matter and Nanosciences - Bio & Soft Matter; Université Catholique de Louvain; Croix du Sud 1/L7.04.01; 1348; Louvain-la-Neuve; Belgium
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21
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Pei X, Fernandes A, Mathy B, Laloyaux X, Nysten B, Riant O, Jonas AM. Correlation between the structure and wettability of photoswitchable hydrophilic azobenzene monolayers on silicon. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:9403-9412. [PMID: 21699194 DOI: 10.1021/la201526u] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Photoresponsive monolayers of hydrophilically substituted azobenzenes have been prepared by reaction on aminosilane monolayers on silicon surfaces. Grafting densities in the 0.2-1.0 molecule/nm(2) range were determined by X-ray reflectometry. The monolayers exhibit reversible photoisomerization, switching from a more hydrophilic trans state to a less hydrophilic cis state upon UV irradiation, in contrast with the usual behavior of most azobenzene monolayers that switch from a less to a more hydrophilic state. This indicates that the wettability is not dominated by the change in the dipole moment of the azobenzene moiety but originates from variations in the composition of the outer surface of the monolayers resulting from the reorientation of the substituent groups. The light-driven change in the water contact angle correlates linearly with the grafting density but remains small. However, the wettability contrast can be increased by forcing the molecules to stand in an improved vertical orientation, either by densifying the underlying aminosilane monolayer or by filling the voids left at the bottom of the layer of grafted azobenzene molecules.
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Affiliation(s)
- Xiaowei Pei
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Croix du Sud 1/4, 1348 Louvain-la-Neuve, Belgium
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22
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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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23
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Qin G, Gu J, Liu K, Xiao Z, Yam CM, Cai C. Conductive AFM patterning on oligo(ethylene glycol)-terminated alkyl monolayers on silicon substrates: proposed mechanism and fabrication of avidin patterns. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:6987-94. [PMID: 21526810 PMCID: PMC3230272 DOI: 10.1021/la1047358] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Micro- and nanopatterns of biomolecules on inert, ultrathin platforms on nonoxidized silicon are ideal interfaces between silicon-based microelectronics and biological systems. We report here the local oxidation nanolithography with conductive atomic force microscopy (cAFM) on highly protein-resistant, oligo(ethylene glycol) (OEG)-terminated alkyl monolayers on nonoxidized silicon substrates. We propose a mechanism for this process, suggesting that it is possible to oxidize only the top ethylene glycol units to generate carboxylic acid and aldehyde groups on the film surface. We show that avidin molecules can be attached selectively to the oxidized pattern and the density can be varied by altering the bias voltage during cAFM patterning. Biotinylated molecules and nanoparticles are selectively immobilized on the resultant avidin patterns. Since one of the most established methods for immobilization of biomolecules is based on avidin-biotin binding and a wide variety of biotinylated biomolecules are available, this approach represents a versatile means for prototyping any nanostructures presenting these biomolecules on silicon substrates.
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Affiliation(s)
| | | | - Kai Liu
- Department of Chemistry, University of Houston, Houston, Texas 77024, United States
| | | | - Chi Ming Yam
- Department of Chemistry, University of Houston, Houston, Texas 77024, United States
| | - Chengzhi Cai
- Department of Chemistry, University of Houston, Houston, Texas 77024, United States
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24
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Radadia AD, Stavis CJ, Carr R, Zeng H, King WP, Carlisle JA, Aksimentiev A, Hamers RJ, Bashir R. Control of Nanoscale Environment to Improve Stability of Immobilized Proteins on Diamond Surfaces. ADVANCED FUNCTIONAL MATERIALS 2011; 21:1040-1050. [PMID: 21949497 PMCID: PMC3177702 DOI: 10.1002/adfm.201002251] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Immunoassays for detection of bacterial pathogens rely on the selectivity and stability of bio-recognition elements such as antibodies tethered to sensor surfaces. The search for novel surfaces that improve the stability of biomolecules and assay performance has been pursued for a long time. However, the anticipated improvements in stability have not been realized in practice under physiological conditions because the surface functionalization layers on commonly used substrates, silica and gold, are themselves unstable on time scales of days. In this paper, we show that covalent linking of antibodies to diamond surfaces leads to substantial improvements in biological activity of proteins as measured by the ability to selectively capture cells of the pathogenic bacterium Escherichia coli O157:H7 even after exposure to buffer solutions at 37 °C for extended periods of time, approaching 2 weeks. Our results from ELISA, XPS, fluorescence microscopy, and MD simulations suggest that by using highly stable surface chemistry and controlling the nanoscale organization of the antibodies on the surface, it is possible to achieve significant improvements in biological activity and stability. Our findings can be easily extended to functionalization of micro and nanodimensional sensors and structures of biomedical diagnostic and therapeutic interest.
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Affiliation(s)
- Adarsh D. Radadia
- Micro and Nanotechnology Laboratory, University of Illinois, 208 North Wright Street, Urbana, Illinois 61801, USA
| | - Courtney J. Stavis
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Rogan Carr
- Department of Physics, University of Illinois, Urbana, IL 61801, USA
| | - Hongjun Zeng
- Advanced Diamond Technologies, Inc, Romeoville, IL 60446, USA
| | - William P. King
- Department of Mechanical Science and Engineering, Micro and Nanotechnology Laboratory, University of Illinois, 208 North Wright Street, Urbana, Illinois 61801, USA
| | | | | | - Robert J. Hamers
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Rashid Bashir
- Micro and Nanotechnology Laboratory, University of Illinois, 208 North Wright Street, Urbana, Illinois 61801, USA
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25
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Cho WK, Kong B, Park HJ, Kim J, Chegal W, Choi JS, Choi IS. Long-term stability of cell micropatterns on poly((3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide)-patterned silicon oxide surfaces. Biomaterials 2010; 31:9565-74. [DOI: 10.1016/j.biomaterials.2010.08.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Accepted: 08/18/2010] [Indexed: 10/18/2022]
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26
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Qin G, Santos C, Zhang W, Li Y, Kumar A, Erasquin UJ, Liu K, Muradov P, Trautner BW, Cai C. Biofunctionalization on alkylated silicon substrate surfaces via "click" chemistry. J Am Chem Soc 2010; 132:16432-41. [PMID: 21033708 PMCID: PMC3059218 DOI: 10.1021/ja1025497] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Biofunctionalization of silicon substrates is important to the development of silicon-based biosensors and devices. Compared to conventional organosiloxane films on silicon oxide intermediate layers, organic monolayers directly bound to the nonoxidized silicon substrates via Si-C bonds enhance the sensitivity of detection and the stability against hydrolytic cleavage. Such monolayers presenting a high density of terminal alkynyl groups for bioconjugation via copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC, a "click" reaction) were reported. However, yields of the CuAAC reactions on these monolayer platforms were low. Also, the nonspecific adsorption of proteins on the resultant surfaces remained a major obstacle for many potential biological applications. Herein, we report a new type of "clickable" monolayers grown by selective, photoactivated surface hydrosilylation of α,ω-alkenynes, where the alkynyl terminal is protected with a trimethylgermanyl (TMG) group, on hydrogen-terminated silicon substrates. The TMG groups on the film are readily removed in aqueous solutions in the presence of Cu(I). Significantly, the degermanylation and the subsequent CuAAC reaction with various azides could be combined into a single step in good yields. Thus, oligo(ethylene glycol) (OEG) with an azido tag was attached to the TMG-alkyne surfaces, leading to OEG-terminated surfaces that reduced the nonspecific adsorption of protein (fibrinogen) by >98%. The CuAAC reaction could be performed in microarray format to generate arrays of mannose and biotin with varied densities on the protein-resistant OEG background. We also demonstrated that the monolayer platform could be functionalized with mannose for highly specific capturing of living targets (Escherichia coli expressing fimbriae) onto the silicon substrates.
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27
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Qin G, Zhang R, Makarenko B, Kumar A, Rabalais W, López Romero JM, Rico R, Cai C. Highly stable, protein resistant thin films on SiC-modified silicon substrates. Chem Commun (Camb) 2010; 46:3289-91. [DOI: 10.1039/b925708j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Kasry A, Borri P, Davies PR, Harwood A, Thomas N, Lofas S, Dale T. Comparison of methods for generating planar DNA-modified surfaces for hybridization studies. ACS APPLIED MATERIALS & INTERFACES 2009; 1:1793-1798. [PMID: 20355796 DOI: 10.1021/am9003073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The surface conformation and accessibility of oligonucleotides within arrays are two key parameters that affect the utility of immobilized nucleic acids in sensor technologies. In this work, a novel combination of analytical techniques was used to compare two methods for DNA immobilization on glass. The aim of the study was to identify a method that generated a high surface density of hybridization-accessible oligonucleotides in a true planar monolayer. The first method based on direct coupling of silanized DNA to the glass surface showed a high immobilization density of 0.013 molecules/nm2 but low surface accessibility, as shown by the hybridization measurements (< or =15%). The second method, based on the biotin-streptavidin interaction, generated a high immobilization density (0.02 molecules/nm2) and high surface accessibility (90%). Atomic force microscopy and X-ray photoelectron spectroscopy indicated that both methods achieved uniform surfaces. Using the biotin-streptavidin system, the intermolecular distance between the hybridized molecules could be tightly controlled by titrating biotinylated complementary and noncomplementary oligonucleotides.
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Affiliation(s)
- Amal Kasry
- Cardiff School of Biosciences, Biomedical Science Building, Museum Avenue, Cardiff CF10 3AX, UK.
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29
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Devouge S, Conti J, Goldsztein A, Gosselin E, Brans A, Voué M, De Coninck J, Homblé F, Goormaghtigh E, Marchand-Brynaert J. Surface functionalization of germanium ATR devices for use in FTIR-biosensors. J Colloid Interface Sci 2008; 332:408-15. [PMID: 19150721 DOI: 10.1016/j.jcis.2008.12.045] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 12/01/2008] [Accepted: 12/17/2008] [Indexed: 11/25/2022]
Abstract
Biosensors based on intrinsic detection methods have attracted growing interest. The use of Fourier transform infra-red (FTIR) spectroscopy with the attenuated internal total reflection (ATR) mode, in the biodetection context, requires appropriate surface functionalization of the ATR optical element. Here, we report the direct grafting of a thin organic layer (about 20 A depth) on the surface of a germanium crystal. This covering, constructed with novel amphiphilic molecules 2b (namely, 2,5,8,11,14,17,20-heptaoxadocosan-22-yl-3-(triethoxysilyl) propylcarbamate), is stable for several hours under phosphate buffered saline (PBS) flux and features protein-repulsive properties. Photografting of molecule 5 (namely, O-succinimidyl 4-(p-azidophenyl)butanoate) affords the activated ATR element, ready for the covalent fixation of receptors, penicillin recognizing proteins BlaR-CTD for instance. The different steps of the previous construction have been monitored by water contact angle (theta(w)) measurements, spectroscopic ellipsometry (covering depth), X-ray photoelectron spectroscopy (XPS) by using a fluorinated tag for the control of surface reactivity, and FTIR-ATR spectroscopy for the structural analysis of grafted molecules. Indeed, contrarily to silicon device, germanium device offers a broad spectral window (1000-4000 cm(-1)) and thus amide I and II absorption bands can be recorded. This work lays the foundations for the construction of novel FTIR biosensors.
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Affiliation(s)
- Sabrina Devouge
- Unité de Chimie Organique et Médicinale, Université Catholique de Louvain, Bâtiment Lavoisier, Place Louis Pasteur 1, B-1348 Louvain-la-Neuve, Belgium
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