301
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Didar TF, Foudeh AM, Tabrizian M. Patterning Multiplex Protein Microarrays in a Single Microfluidic Channel. Anal Chem 2011; 84:1012-8. [DOI: 10.1021/ac2025877] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tohid Fatanat Didar
- Department
of Biomedical Engineering, ‡Faculty of Dentistry, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Amir M. Foudeh
- Department
of Biomedical Engineering, ‡Faculty of Dentistry, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Maryam Tabrizian
- Department
of Biomedical Engineering, ‡Faculty of Dentistry, McGill University, Montreal, Quebec H3A 2B4, Canada
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302
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Xue A, Zhou S, Zhao Y, Lu X, Han P. Effective NH2-grafting on attapulgite surfaces for adsorption of reactive dyes. JOURNAL OF HAZARDOUS MATERIALS 2011; 194:7-14. [PMID: 21959185 DOI: 10.1016/j.jhazmat.2011.06.018] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 06/02/2011] [Accepted: 06/07/2011] [Indexed: 05/31/2023]
Abstract
The amine moiety has an important function in many applications, including, adsorption, catalysis, electrochemistry, chromatography, and nanocomposite materials. We developed an effective adsorbent for aqueous reactive dye removal by modifying attapulgite with an amino-terminated organosilicon (3-aminopropyltriethoxysilane, APTES). Surface properties of the APTES-modified attapulgite were characterized by the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption. We evaluated the impact of solvent, APTES concentration, water volume, reaction time, and temperature on the surface modification. NH(2)-attapulgite was used to remove reactive dyes in aqueous solution and showed very high adsorption rates of 99.32%, 99.67%, and 96.42% for Reactive Red 3BS, Reactive Blue KE-R and Reactive Black GR, respectively. These powerful dye removal effects were attributed to strong electrostatic interactions between reactive dyes and the grafted NH(2) groups.
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Affiliation(s)
- Ailian Xue
- College of Chemistry and Chemical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing 210009, Jiangsu Province, PR China
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303
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Gheorghe DE, Cui L, Karmonik C, Brazdeikis A, Penaloza JM, Young JK, Drezek RA, Bikram M. Gold-silver alloy nanoshells: a new candidate for nanotherapeutics and diagnostics. NANOSCALE RESEARCH LETTERS 2011; 6:554. [PMID: 21995302 PMCID: PMC3212091 DOI: 10.1186/1556-276x-6-554] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 10/13/2011] [Indexed: 05/23/2023]
Abstract
We have developed novel gold-silver alloy nanoshells as magnetic resonance imaging (MRI) dual T1 (positive) and T2 (negative) contrast agents as an alternative to typical gadolinium (Gd)-based contrast agents. Specifically, we have doped iron oxide nanoparticles with Gd ions and sequestered the ions within the core by coating the nanoparticles with an alloy of gold and silver. Thus, these nanoparticles are very innovative and have the potential to overcome toxicities related to renal clearance of contrast agents such as nephrogenic systemic fibrosis. The morphology of the attained nanoparticles was characterized by XRD which demonstrated the successful incorporation of Gd(III) ions into the structure of the magnetite, with no major alterations of the spinel structure, as well as the growth of the gold-silver alloy shells. This was supported by TEM, ICP-AES, and SEM/EDS data. The nanoshells showed a saturation magnetization of 38 emu/g because of the presence of Gd ions within the crystalline structure with r1 and r2 values of 0.0119 and 0.9229 mL mg-1 s-1, respectively (Au:Ag alloy = 1:1). T1- and T2-weighted images of the nanoshells showed that these agents can both increase the surrounding water proton signals in the T1-weighted image and reduce the signal in T2-weighted images. The as-synthesized nanoparticles exhibited strong absorption in the range of 600-800 nm, their optical properties being strongly dependent upon the thickness of the gold-silver alloy shell. Thus, these nanoshells have the potential to be utilized for tumor cell ablation because of their absorption as well as an imaging agent.
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Affiliation(s)
- Dana E Gheorghe
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas Medical Center Campus, 1441 Moursund St., Houston, TX 77030, USA
| | - Lili Cui
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas Medical Center Campus, 1441 Moursund St., Houston, TX 77030, USA
| | | | - Audrius Brazdeikis
- Department of Physics and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Houston, TX 77004, USA
| | - Jose M Penaloza
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas Medical Center Campus, 1441 Moursund St., Houston, TX 77030, USA
| | - Joseph K Young
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, MS-366, Houston, TX 77005, USA
| | - Rebekah A Drezek
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, MS-366, Houston, TX 77005, USA
- Department of Bioengineering, Rice University, 6100 Main Street, MS-142, Houston, TX 77005, USA
| | - Malavosklish Bikram
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas Medical Center Campus, 1441 Moursund St., Houston, TX 77030, USA
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304
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Shircliff RA, Martin IT, Pankow JW, Fennell J, Stradins P, Ghirardi ML, Cowley SW, Branz HM. High-resolution X-ray photoelectron spectroscopy of mixed silane monolayers for DNA attachment. ACS APPLIED MATERIALS & INTERFACES 2011; 3:3285-3292. [PMID: 21797205 DOI: 10.1021/am200604q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The amine density of 3-aminopropyldimethylethoxysilane (APDMES) films on silica is controlled to determine its effect on DNA probe density and subsequent DNA hybridization. The amine density is tailored by controlling the surface reaction time of (1) APDMES, or (2) n-propyldimethylchlorosilane (PDMCS, which is not amine terminated) and then reacting it with APDMES to form a mixed monolayer. High-resolution X-ray photoelectron spectroscopy (XPS) is used to quantify silane surface coverage of both pure and mixed monolayers on silica; the XPS data demonstrate control of amine density in both pure APDMES and PDMCS/APDMES mixed monolayers. A linear correlation between the atomic concentration of N atoms from the amine and Si atoms from the APDMES in pure APDMES films allows us to calculate the PDMCS/APDMES ratio in the mixed monolayers. Fluorescence from attached DNA probes and from hybridized DNA decreases as the percentage of APDMES in the mixed monolayer is decreased by dilution with PDMCS.
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Affiliation(s)
- Rebecca A Shircliff
- Chemistry and Geochemistry Department, Colorado School of Mines, Golden, Colorado 80401, United States
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305
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Zhang Z, Wu Y. NaBH4-induced assembly of immobilized Au nanoparticles into chainlike structures on a chemically modified glass surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:9834-9842. [PMID: 21728373 DOI: 10.1021/la201943u] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A facile method of obtaining chainlike assemblies of gold nanoparticles (AuNPs) on a chemically modified glass surface based on NaBH(4) treatment is developed. Citrate-stabilized AuNPs (17 nm) are immobilized on a glutaraldehyde-functionalized glass surface and assembled into chainlike structures after treatment with aqueous sodium borohydride (NaBH(4)) solution. The production and morphology of the AuNP chainlike assemblies are controlled by the density of the immobilized NPs, the concentration of NaBH(4) solution, and the treatment time. The AuNP assemblies are stable in water and can undergo drying. X-ray photoelectron spectroscopic data show that the number of citrate ions on the AuNPs decreased by 43% after treatment with 5 mg/mL NaBH(4) solution. The NaBH(4)-induced partial removal of the citrate ions and the roughness of the glass surface greatly affect the binding force of AuNPs on the substrate. The immobilized AuNPs begin to move at the solid-liquid interface without desorbing when the strength of the binding force was decreased. These mobile NPs form chainlike assemblies under the driving force of van der Waals interaction and diffusion. This interface-based formation of chainlike assemblies of AuNPs may provide a simple protocol for the 1D assembly of other Au-coated colloidal nanoparticles.
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Affiliation(s)
- Zhiqiang Zhang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, PR China
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306
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Vasani RB, McInnes SJP, Cole MA, Jani AMM, Ellis AV, Voelcker NH. Stimulus-responsiveness and drug release from porous silicon films ATRP-grafted with poly(N-isopropylacrylamide). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:7843-7853. [PMID: 21604788 DOI: 10.1021/la200551g] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this report, we employ surface-initiated atom transfer radical polymerization (SI-ATRP) to graft a thermoresponsive polymer, poly(N-isopropylacrylamide) (PNIPAM), of controlled thickness from porous silicon (pSi) films to produce a stimulus-responsive inorganic-organic composite material. The optical properties of this material are studied using interferometric reflectance spectroscopy (IRS) above and below the lower critical solution temperature (LCST) of the PNIPAM graft polymer with regard to variation of pore sizes and thickness of the pSi layer (using discrete samples and pSi gradients) and also the thickness of the PNIPAM coatings. Our investigations of the composite's thermal switching properties show that pore size, pSi layer thickness, and PNIPAM coating thickness critically influence the material's thermoresponsiveness. This composite material has considerable potential for a range of applications including temperature sensors and feedback controlled drug release. Indeed, we demonstrate that modulation of the temperature around the LCST significantly alters the rate of release of the fluorescent anticancer drug camptothecin from the pSi-PNIPAM composite films.
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Affiliation(s)
- Roshan B Vasani
- School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042, Australia
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307
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Nejadnik MR, Deepak FL, Garcia CD. Adsorption of Glucose Oxidase to 3-D Scaffolds of Carbon Nanotubes: Analytical Applications. ELECTROANAL 2011; 23:1462-1469. [PMID: 22735356 PMCID: PMC3380380 DOI: 10.1002/elan.201000758] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 02/07/2011] [Indexed: 01/21/2023]
Abstract
This study is the first to focus on the potential use of carbon nanotube (CNT) scaffolds as enzyme immobilization substrates for analytical purposes. Besides all the well-known advantages of CNT, three-dimensional scaffolds can significantly increase the amount of enzymes adsorbed per unit area, preserve the catalytic activity of the adsorbed molecules, and allow effective exposure to substrates present in the adjacent medium. Additionally, our results indicate that the sensitivity of analytical probes based on enzyme-loaded CNT scaffolds is proportional to the thickness of the scaffold providing 3-fold sensitivity improvements with respect to the control surfaces.
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Affiliation(s)
- M. Reza Nejadnik
- Department of Chemistry University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249 USA
| | - Francis L. Deepak
- Department of Physics and Astronomy University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249 USA
| | - Carlos D. Garcia
- Department of Chemistry University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249 USA
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308
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Kim J, Holinga GJ, Somorjai GA. Curing induced structural reorganization and enhanced reactivity of amino-terminated organic thin films on solid substrates: observations of two types of chemically and structurally unique amino groups on the surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5171-5175. [PMID: 21476532 DOI: 10.1021/la2007205] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Infrared-visible sum frequency generation vibrational spectroscopy (SFG) was used to characterize the structure of 3-aminopropyltriethoxysilane (APTES) films deposited on solid substrates under controlled experimental conditions for the first time. Our SFG spectra in combination with complementary analytical data showed that APTES films undergo structural changes when cured at an elevated temperature. Before the films are cured, well-ordered hydrophobic ethoxy groups are dominantly present on the surface. A majority of hydrophilic surface amino groups are protonated, and they are either buried or randomly oriented at the interface. After the films are cured, chemically and structurally different neutral amino groups are detected on the surface. Unlike the protonated amino groups, a new class of neutral amino groups is ordered at the interface and shows enhanced reactivity.
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Affiliation(s)
- Joonyeong Kim
- Department of Chemistry, Buffalo State, State University of New York, 1300 Elmwood Avenue, Buffalo, New York 14222, United States.
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309
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Tong Y, Tyrode E, Osawa M, Yoshida N, Watanabe T, Nakajima A, Ye S. Preferential adsorption of amino-terminated silane in a binary mixed self-assembled monolayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5420-5426. [PMID: 21456609 DOI: 10.1021/la200497u] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The composition and structure of a binary mixed self-assembled monolayer (SAM) of 3-aminopropyltriethoxysilane (APS, NH(2)(CH(2))(3)Si(OCH(2)CH(3))(3)) and octadecyltrimethoxysilane (ODS, CH(3)(CH(2))(17)Si(OCH(3))(3)) on a silicon oxide surface have been characterized by water contact-angle measurements, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and sum frequency generation (SFG) vibrational spectroscopy. XPS demonstrated that APS in the mixed SAM is significantly enriched in comparison to that in solution, indicating the preferential adsorption of APS during the SAM formation. AFM observations showed that the mixed SAM becomes rougher. SFG revealed that the coadsorption of APS induced a conformation disordering in the ODS molecules present in the mixed SAM. The surface enrichment of APS has been explained in terms of differences in the surface adsorption rates of the two components as well as in the self-congregation states of APS molecules in the bulk solution. Furthermore, the structure of the water molecules on the mixed SAM surface in contact with the aqueous solutions at different pH's has also been studied. The results indicate that the mixed-SAM modified surface is positively charged at pH < 5 and negatively charged at pH > 7.
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Affiliation(s)
- Yujin Tong
- Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan
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310
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Bellan LM, Wu D, Langer RS. Current trends in nanobiosensor technology. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2011; 3:229-46. [PMID: 21391305 PMCID: PMC4126610 DOI: 10.1002/wnan.136] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The development of tools and processes used to fabricate, measure, and image nanoscale objects has lead to a wide range of work devoted to producing sensors that interact with extremely small numbers (or an extremely small concentration) of analyte molecules. These advances are particularly exciting in the context of biosensing, where the demands for low concentration detection and high specificity are great. Nanoscale biosensors, or nanobiosensors, provide researchers with an unprecedented level of sensitivity, often to the single molecule level. The use of biomolecule-functionalized surfaces can dramatically boost the specificity of the detection system, but can also yield reproducibility problems and increased complexity. Several nanobiosensor architectures based on mechanical devices, optical resonators, functionalized nanoparticles, nanowires, nanotubes, and nanofibers have been demonstrated in the lab. As nanobiosensor technology becomes more refined and reliable, it is likely it will eventually make its way from the lab to the clinic, where future lab-on-a-chip devices incorporating an array of nanobiosensors could be used for rapid screening of a wide variety of analytes at low cost using small samples of patient material.
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Affiliation(s)
- Leon M Bellan
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
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311
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Ombelli M, Costello L, Postle C, Anantharaman V, Meng QC, Composto RJ, Eckmann DM. Competitive protein adsorption on polysaccharide and hyaluronate modified surfaces. BIOFOULING 2011; 27:505-518. [PMID: 21623481 PMCID: PMC3105331 DOI: 10.1080/08927014.2011.585711] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Adsorption of bovine serum albumin (BSA) and fibrinogen (Fg) was measured on six distinct bare and dextran- and hyaluronate-modified silicon surfaces created using two dextran grafting densities and three hyaluronic acid (HA) sodium salts derived from human umbilical cord, rooster comb and Streptococcus zooepidemicus. Film thickness and surface morphology depended on the HA molecular weight and concentration. BSA coverage was enhanced on surfaces in competitive adsorption of BSA:Fg mixtures. Dextranization differentially reduced protein adsorption onto surfaces based on oxidation state. Hyaluronization was demonstrated to provide the greatest resistance to protein coverage, equivalent to that of the most resistant dextranized surface. Resistance to protein adsorption was independent of the type of HA utilized. With changing bulk protein concentration from 20 to 40 μg ml(-1) for each species, Fg coverage on silicon increased by 4x, whereas both BSA and Fg adsorption on dextran and HA were far less dependent on protein bulk concentration.
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Affiliation(s)
- Michela Ombelli
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104
| | - Lauren Costello
- Department of Material Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Corinne Postle
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104
| | - Vinod Anantharaman
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104
| | - Qing Cheng Meng
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104
| | - Russell J. Composto
- Department of Material Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104
| | - David M. Eckmann
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104
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312
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Tsai IY, Tomczyk N, Eckmann JI, Composto RJ, Eckmann DM. Human plasma protein adsorption onto dextranized surfaces: a two-dimensional electrophoresis and mass spectrometry study. Colloids Surf B Biointerfaces 2011; 84:241-52. [PMID: 21277175 PMCID: PMC3079350 DOI: 10.1016/j.colsurfb.2011.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 12/29/2010] [Accepted: 01/06/2011] [Indexed: 11/19/2022]
Abstract
Protein adsorption is fundamental to thrombosis and to the design of biocompatible materials. We report a two-dimensional electrophoresis and mass spectrometry study to characterize multiple human plasma proteins adsorbed onto four different types of model surfaces: silicon oxide, dextranized silicon, polyurethane and dextranized polyurethane. Dextran was grafted onto the surfaces of silicon and polyurethane to mimic the blood-contacting endothelial cell glycocalyx surface. Surface topography and hydrophobicity/hydrophilicity were determined and analyzed using atomic force microscopy and water contact angle measurements, respectively. Using two-dimensional electrophoresis, we show that, relative to the unmodified surfaces, dextranization significantly inhibits the adsorption of several human plasma proteins including IGHG1 protein, fibrinogen, haptoglobin, Apo A-IV, Apo A-I, immunoglobulin, serum retinal-binding protein and truncated serum albumin. We further demonstrate the selectivity of plasma protein adsorbed onto the different functionalized surfaces and the potential to control and manipulate proteins adsorption on the surfaces of medical devices, implants and microfluidic devices. This result shows that adsorption experiments using a single protein or a binary mixture of proteins are consistent with competitive protein adsorption studies. In summary, these studies indicate that coating blood-contacting biomedical applications with dextran is an effective route to reduce thrombo-inflammatory responses and to surface-direct biological activities.
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Affiliation(s)
- Irene Y. Tsai
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nancy Tomczyk
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joshua I. Eckmann
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Russell J. Composto
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David M. Eckmann
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104, USA
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313
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Ehlert N, Hoffmann A, Luessenhop T, Gross G, Mueller PP, Stieve M, Lenarz T, Behrens P. Amino-modified silica surfaces efficiently immobilize bone morphogenetic protein 2 (BMP2) for medical purposes. Acta Biomater 2011; 7:1772-9. [PMID: 21187169 DOI: 10.1016/j.actbio.2010.12.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 12/06/2010] [Accepted: 12/21/2010] [Indexed: 11/16/2022]
Abstract
Due to its ability to induce de novo bone formation the differentiation factor bone morphogenetic protein 2 (BMP2) is often used to enhance the integration of bone implants. With the aim of reducing possible high dose side-effects and to lower the costs, in order to produce affordable implants, we developed a simple and fast method for the immobilization of BMP2 on silica-based surfaces using silane linkers which carry amino or epoxy functions. We put an especial emphasis on the influence of the nanoscale surface topography of the silica layer. Therefore, we chose glass (for control experiments) and Bioverit® II (as a typical implant base material) as support materials and coated these substrates with unstructured or nanoporous amorphous silica layers for comparison. Immobilized BMP2 was quantified by two different methods: by ELISA and by a cell-based assay for active BMP2. These tests probe for immunologically and biologically active BMP2, respectively. The results show that the amino functionalization is better suited for immobilizing the protein. Strikingly, a considerably higher amount of BMP2 could be immobilized on coated Bioverit® II surfaces compared with coated glass substrates, which was presumably due to the macroscopic roughness of the Bioverit® II substrates. In addition, it was found that the nanoporous silica coatings on Bioverit® II substrates were able to bind more BMP2 than the unstructured ones.
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Affiliation(s)
- Nina Ehlert
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
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314
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Wei MY, Leon LJ, Lee Y, Parks D, Carroll L, Famouri P. Selective attachment of F-actin with controlled length for developing an intelligent nanodevice. J Colloid Interface Sci 2011; 356:182-9. [DOI: 10.1016/j.jcis.2010.12.079] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 12/23/2010] [Accepted: 12/27/2010] [Indexed: 10/18/2022]
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315
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Yan Z, Sun Z, Lu W, Yao J, Zhu Y, Tour JM. Controlled modulation of electronic properties of graphene by self-assembled monolayers on SiO2 substrates. ACS NANO 2011; 5:1535-1540. [PMID: 21291198 DOI: 10.1021/nn1034845] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this study, with self-assembled monolayers (SAMs) of aminopropyl-, ammoniumpropyl-, butyl-, and 1H,1H,2H,2H-perfluorooctyltriethoxysilanes deposited in-between graphene and the SiO(2) substrate, a controlled doping of graphene was realized with a threshold voltage ranging from -18 to 30 V. In addition, the SAMs are covalently bonded to the SiO(2) surface rather than the graphene surface, thereby producing minimal effects on the mobility of the graphene. Finally, it is more stable than conventional noncovalent dopants.
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Affiliation(s)
- Zheng Yan
- Richard E. Smalley Institute for Nanoscale Science and Technology, Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA
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316
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Rother D, Sen T, East D, Bruce IJ. Silicon, silica and its surface patterning/activation with alkoxy- and amino-silanes for nanomedical applications. Nanomedicine (Lond) 2011; 6:281-300. [DOI: 10.2217/nnm.10.159] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Silica and silicates are widely used in nanomedicine with applications as diverse as medical device coatings to replacement materials in tissue engineering. Although much is known about silica and its synthesis, relatively few biomedical scientists fully appreciate the link that exists between its formulation and its resultant structure and function. This article attempts to provide insight into relevant issues in that context, as well as highlighting their importance in the material’s eventual surface patterning/activation with alkoxy- and organo-silanes. The use of aminosilanes in that context is discussed at some length to permit an understanding of the specific variables that are important in the reproducible and robust aminoactivation of surfaces using such molecules. Recent investigative work is cited to underline the fact that although aminosilanization is a historically accepted mechanism for surface activation, there is still much to be explained about how and why the process works in the way it does. In the last section of this article, there is a detailed discussion of two classical approaches for the use of aminosilanized materials in the covalent immobilization of bioligands, amino-aldehyde and amino-carboxyl coupling. In the former case, the use of the homobifunctional coupler glutaraldehyde is explored, and in the latter, carbodiimides. Although these chemistries have long been employed in bioconjugations, it is apparent that there are still variables to be explored in the processes (as witnessed by continuing investigations into the chemistries concerned). Aspects regarding optimization, standardization and reproducibility of the fabrication of amino functionalized surfaces are discussed in detail and illustrated with practical examples to aid the reader in their own studies, in terms of considerations to be taken into account when producing such materials. Finally, the article attempts to remind readers that although the chemistry and materials involved are ‘old hat’, there is still much to be learnt about the methods involved. The article also reminds readers that although many highly specific and costly conjugation chemistries now exist for bioligands, there still remains a place for these relatively simple and cost-effective approaches in bioligand conjugate fabrication.
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Affiliation(s)
- Dag Rother
- Nanobiotechnology Research Group, School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK
- Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, Freidrich-Henkel-Weg 1-25 D-44149 Dortmund, Germany
| | - Tapas Sen
- Nanobiotechnology Research Group, School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK
- Centre for Materials Science, School of Forensic & Investigative Sciences, University of Central Lancashire, Preston, PR1 2HE, UK
| | - Daniel East
- Nanobiotechnology Research Group, School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK
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317
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Zhou H, Bent SF. Molecular layer deposition of functional thin films for advanced lithographic patterning. ACS APPLIED MATERIALS & INTERFACES 2011; 3:505-11. [PMID: 21302918 DOI: 10.1021/am1010805] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Photoresist materials comprise one of the main challenges faced by lithography to meet the requirements of electronic device size scaling. Here we report for the first time the use of molecular layer deposition (MLD) to produce photoresist materials with controllable placement of functional moieties. Polyurea resists films are deposited by MLD using urea coupling reactions between 1,4-phenylene diisocyanate (PDIC) and ethylenediamine (ED) or 2,2'-(propane-2,2-diylbis(oxy))diethanamine (PDDE) monomers in a layer-by-layer fashion with a linear growth rate, allowing acid-labile groups to be incorporated into the film at well-controlled positions. The films are deposited with stoichiometric compositions and have highly uniform surface morphology as investigated using atomic force microscopy. We show that acid treatment can cleave the backbone of the polyurea film at positions where the acid-labile groups are embedded. We further show that after soaking the polyurea film with photoacid generator (PAG), it acts as a photoresist material and we present several UV patterning demonstrations. This approach presents a new way to make molecularly designed resist films for lithography.
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Affiliation(s)
- Han Zhou
- Department of Chemistry, Stanford University, USA
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318
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Song J, Kong H, Jang J. Bacterial adhesion inhibition of the quaternary ammonium functionalized silica nanoparticles. Colloids Surf B Biointerfaces 2011; 82:651-6. [DOI: 10.1016/j.colsurfb.2010.10.027] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 10/01/2010] [Accepted: 10/11/2010] [Indexed: 10/18/2022]
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319
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Esfandiari NM, Wang Y, McIntire TM, Blum SA. Real-Time Imaging of Platinum−Sulfur Ligand Exchange Reactions at the Single-Molecule Level via a General Chemical Technique. Organometallics 2011. [DOI: 10.1021/om100911n] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- N. Melody Esfandiari
- Department of Chemistry, University of California at Irvine, Irvine, California 92697, United States
| | - Yong Wang
- Department of Chemistry, University of California at Irvine, Irvine, California 92697, United States
| | - Theresa M. McIntire
- Department of Chemistry, University of California at Irvine, Irvine, California 92697, United States
| | - Suzanne A. Blum
- Department of Chemistry, University of California at Irvine, Irvine, California 92697, United States
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320
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Ray D, Belin C, Hui F, Fabre B, Hapiot P, Bassani DM. Direct formation of fullerene monolayers using [4+2] Diels–Alder cycloaddition. Chem Commun (Camb) 2011; 47:2547-9. [DOI: 10.1039/c0cc04899b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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321
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Abstract
Atomic force microscopy (AFM) works by scanning a very tiny tip over a surface with great precision. The microscope tips can be chemically functionalized to improve the images obtained. Well-defined chemical functionalization of AFM tips is especially important for experiments, such as chemical force microscopy and single molecule recognition force microscopy, to examine specific interactions at the single molecular level. In this chapter, we present an overview of chemical modifications of tips that have been reported to date with regards to the proper fixation of probe molecules, focusing particularly on chemical procedures developed to anchor biological molecules on AFM tips.
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Affiliation(s)
- Régis Barattin
- Département de chimie, Université Laval, Quebec, QC, Canada
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322
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Kim J. Formation, Structure, and Reactivity of Amino-Terminated Organic Films on Silicon Substrates. ACS SYMPOSIUM SERIES 2011. [DOI: 10.1021/bk-2011-1062.ch006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Joonyeong Kim
- Department of Chemistry, Buffalo State, State University of New York, 1300 Elmwood Avenue, Buffalo, New York 14222
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323
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Yao J, Zhong L, Natelson D, Tour JM. Silicon oxide: a non-innocent surface for molecular electronics and nanoelectronics studies. J Am Chem Soc 2010; 133:941-8. [PMID: 21175171 DOI: 10.1021/ja108277r] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Silicon oxide (SiO(x)) has been widely used in many electronic systems as a supportive and insulating medium. Here, we demonstrate various electrical phenomena such as resistive switching and related nonlinear conduction, current hysteresis, and negative differential resistance intrinsic to a thin layer of SiO(x). These behaviors can largely mimic numerous electrical phenomena observed in molecules and other nanomaterials, suggesting that substantial caution should be paid when studying conduction in electronic systems with SiO(x) as a component. The actual electrical phenomena can be the result of conduction from SiO(x) at a post soft-breakdown state and not the presumed molecular or nanomaterial component. These electrical properties and the underlying mechanisms are discussed in detail.
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Affiliation(s)
- Jun Yao
- Applied Physics Program through the Department of Bioengineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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324
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Zeng X, Xu G, Gao Y, An Y. Surface Wettability of (3-Aminopropyl)triethoxysilane Self-Assembled Monolayers. J Phys Chem B 2010; 115:450-4. [DOI: 10.1021/jp109259b] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiangxuan Zeng
- Department of Chemical Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Guohua Xu
- Department of Chemical Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Yuan Gao
- Department of Chemical Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Yue An
- Department of Chemical Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
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325
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Kroll S, Treccani L, Rezwan K, Grathwohl G. Development and characterisation of functionalised ceramic microtubes for bacteria filtration. J Memb Sci 2010. [DOI: 10.1016/j.memsci.2010.09.045] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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326
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Estephan ZG, Jaber JA, Schlenoff JB. Zwitterion-stabilized silica nanoparticles: toward nonstick nano. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:16884-16889. [PMID: 20942453 DOI: 10.1021/la103095d] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Using a short-chain zwitterionic organosiloxane, silica nanoparticles were stabilized against aggregation by high ionic strength and/or proteins. Turbidimetry and dynamic light scattering showed that "zwitterated" nanoparticles did not exhibit a significant increase in hydrodynamic radius. When challenged with 3 M NaCl or 50% fetal bovine serum, aggregation was inhibited for at least 24 h, longer with mild heat treatment, which produced nanoparticles with zero net surface charge. These findings suggest "zwitteration" of silica-capped nanoparticles provides excellent stability for in vivo circulation diagnostics and therapies.
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Affiliation(s)
- Zaki G Estephan
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, Florida 32306, United States
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327
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Miletić N, Fahriansyah, Nguyen LTT, Loos K. Formation, topography and reactivity ofCandida antarcticalipase B immobilized on silicon surface. BIOCATAL BIOTRANSFOR 2010. [DOI: 10.3109/10242422.2010.531712] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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328
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Jackson AC, Bartelt JA, Marczewski K, Sottos NR, Braun PV. Silica-Protected Micron and Sub-Micron Capsules and Particles for Self-Healing at the Microscale. Macromol Rapid Commun 2010; 32:82-7. [DOI: 10.1002/marc.201000468] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Indexed: 11/11/2022]
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329
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Awsiuk K, Bernasik A, Kitsara M, Budkowski A, Rysz J, Haberko J, Petrou P, Beltsios K, Raczkowska J. Protein coverage on silicon surfaces modified with amino-organic films: A study by AFM and angle-resolved XPS. Colloids Surf B Biointerfaces 2010; 80:63-71. [DOI: 10.1016/j.colsurfb.2010.05.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 05/21/2010] [Accepted: 05/22/2010] [Indexed: 10/19/2022]
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330
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Zhang F, Sautter K, Larsen AM, Findley DA, Davis RC, Samha H, Linford MR. Chemical vapor deposition of three aminosilanes on silicon dioxide: surface characterization, stability, effects of silane concentration, and cyanine dye adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14648-14654. [PMID: 20731334 DOI: 10.1021/la102447y] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Covalently bonded monolayers of two monofunctional aminosilanes (3-aminopropyldimethylethoxysilane, APDMES, and 3-aminopropyldiisopropylethoxysilane, APDIPES) and one trifunctional aminosilane (3-aminopropyltriethoxysilane, APTES) have been deposited on dehydrated silicon substrates by chemical vapor deposition (CVD) at 150 °C and low pressure (a few Torr) using reproducible equipment. Standard surface analytical techniques such as x-ray photoelectron spectroscopy (XPS), contact angle goniometry, spectroscopic ellipsometry, atomic force microscopy, and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) have been employed to characterize the resulting films. These methods indicate that essentially constant surface coverages are obtained over a wide range of gas phase concentrations of the aminosilanes. XPS data further indicate that the N1s/Si2p ratio is higher after CVD with the trifunctional silane (APTES) compared to the monofunctional ones, with a higher N1s/Si2p ratio for APDMES compared to that for APDIPES. AFM images show an average surface roughness of 0.12- 0.15 nm among all three aminosilane films. Stability tests indicate that APDIPES films retain most of their integrity at pH 10 for several hours and are more stable than APTES or APDMES layers. The films also showed good stability against storage in the laboratory. ToF-SIMS of these samples showed expected peaks, such as CN(-), as well as CNO(-), which may arise from an interaction between monolayer amine groups and silanols. Optical absorption measurements on adsorbed cyanine dye at the surface of the aminosilane films show the formation of dimer aggregates on the surface. This is further supported by ellipsometry measurements. The concentration of dye on each surface appears to be consistent with the density of the amines.
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Affiliation(s)
- Feng Zhang
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
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331
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Esfandiari NM, Wang Y, Bass JY, Cornell TP, Otte DAL, Cheng MH, Hemminger JC, McIntire TM, Mandelshtam VA, Blum SA. Single-Molecule Imaging of Platinum Ligand Exchange Reaction Reveals Reactivity Distribution. J Am Chem Soc 2010; 132:15167-9. [DOI: 10.1021/ja105517d] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
| | - Yong Wang
- Department of Chemistry, University of California, Irvine, California 92697
| | - Jonathan Y. Bass
- Department of Chemistry, University of California, Irvine, California 92697
| | - Trevor P. Cornell
- Department of Chemistry, University of California, Irvine, California 92697
| | - Douglas A. L. Otte
- Department of Chemistry, University of California, Irvine, California 92697
| | - Ming H. Cheng
- Department of Chemistry, University of California, Irvine, California 92697
| | - John C. Hemminger
- Department of Chemistry, University of California, Irvine, California 92697
| | | | | | - Suzanne A. Blum
- Department of Chemistry, University of California, Irvine, California 92697
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332
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Stratton TR, Howarter JA, Allison BC, Applegate BM, Youngblood JP. Structure-activity relationships of antibacterial and biocompatible copolymers. Biomacromolecules 2010; 11:1286-90. [PMID: 20380430 DOI: 10.1021/bm1000839] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The development of polymers that are both bactericidal and biocompatible would have many applications and are currently of research interest. Following the development of strongly bactericidal copolymers of 4-vinylpyridine and poly(ethylene glycol) methyl ether methacrylate, biocompatibility assays have been completed on these materials to measure their potential biocompatibility. In this article, a new methodology for measuring protein interaction was developed for water-soluble polymers by coupling proteins to surfaces and then measuring the adsorption of copolymers onto these surfaces. Ellipsometry was then used to measure the thickness of adsorbed polymers as a measurement of biocompatibility. These results were then compared and correlated with the results of other biocompatibility assays previously conducted on these polymers, affording a greater understanding of the biocompatibility of the copolymers as well as improving the understanding of the effect of hydrophilic and hydrophobic groups that is vital for the development of these materials.
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Affiliation(s)
- Thomas R Stratton
- School of Materials Engineering, Purdue University, West Lafayette, Indiana, USA
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333
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334
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Engel Y, Elnathan R, Pevzner A, Davidi G, Flaxer E, Patolsky F. Supersensitive Detection of Explosives by Silicon Nanowire Arrays. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201000847] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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335
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Gao B, Sarveswaran K, Bernstein GH, Lieberman M. Guided deposition of individual DNA nanostructures on silicon substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:12680-12683. [PMID: 20590122 DOI: 10.1021/la101343k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate immobilization of DNA nanostructures (37 nm x 8 nm) on silicon by a combination of "top-down" fabrication and "bottom-up" self-assembly. Anchor lines and pads were defined using electron beam lithography and a cationic molecular monolayer. Individual DNA nanostructures bind in 85% yield onto the anchor pads and can be washed and imaged in air. The strength of the binding interaction between a DNA nanostructure and its anchor pad is at least -43 kJ/mol.
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Affiliation(s)
- Bo Gao
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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336
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Ah CS, Kim AS, Kim WJ, Park CW, Ahn CG, Yang JH, Baek IB, Kim TY, Sung GY. Electronic Detection of Biomarkers by Si Field-Effect Transistor from Undiluted Sample Solutions with High Ionic Strengths. B KOREAN CHEM SOC 2010. [DOI: 10.5012/bkcs.2010.31.6.1561] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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337
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Zhang Z, Wu Y. Investigation of the NaBH4-induced aggregation of Au nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:9214-9223. [PMID: 20465205 DOI: 10.1021/la904410f] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Colloidal Au nanoparticles (AuNPs) with a diameter of 17 nm were prepared by the reduction of HAuCl(4) with citrate trisodium. The addition of NaBH(4) to the prepared citrate-stabilized AuNP solutions not only induced a blue shift in the surface plasmon resonance peak (lambda(max)) because of the increased number of electrons in the NPs injected by NaBH(4) but also affected the stability of citrate adsorbed on AuNPs. The zeta potential of AuNPs after the addition of 6 mM NaBH(4) decreased (67%) but was restored (88%) after the discharge of the injected electrons. The effect of NaBH(4) treatment on the stability of citrate ions on AuNPs was investigated by X-ray photoelectron spectroscopy (XPS). The XPS data showed that citrate ions partially desorbed from the surfaces of AuNPs (67%) after NaBH(4) treatment but readsorbed onto the AuNPs (80%) after the discharge of the NPs; this result agrees well with the zeta potential data. The partial removal of citrate ions from AuNPs results in an anisotropic charge distribution around the AuNPs. By increasing the amount of NaBH(4) and the electrolyte concentration of the solution, non-close-packed aggregates of AuNPs can be formed, from monomers to small aggregates containing a few AuNPs and 3D network aggregates.
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Affiliation(s)
- Zhiqiang Zhang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jilin Province 130033, PR China
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338
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Rébiscoul D, Perrut V, Morel T, Jayet C, Cubitt R, Haumesser PH. Alkoxysilane layers compatible with copper deposition for advanced semiconductor device applications. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8981-8987. [PMID: 20187647 DOI: 10.1021/la904771s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Alkoxysilane having various functional headgroups (amino and mercapto) and morphologies was deposited by supercritical CO(2) onto a porous dielectric material to replace the metallic barrier used in semiconductor devices. These organic layers were successfully coated with Cu. The morphologies of the stacks were investigated by X-ray and neutron reflectometry and atomic force microscopy. Whereas PVD Cu deposition is not adapted to silanized dielectric material with mercapto and aminopropyltrimethoxysilane but acceptable with aminoethylaminopropyltrimethoxysilane, the MOCVD process is more interesting. XRR and NR data clearly indicate that silane layers remain intact after copper deposition and, depending on the Cu immobilization capability of the chemical function of the silane and its orientation into the layer, the Cu film morphologies are different. Dense, thin films having small Cu grains were obtained with an aminoethylaminopropyltrimethoxysilane layer, and thick films having a low density and large Cu grains were obtained with an aminopropyltrimethoxysilane layer. Nucleation and growth mechanisms are discussed.
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339
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Sun X, Wei W. Electrostatic-assembly-driven formation of micrometer-scale supramolecular sheets of (3-aminopropyl)triethoxysilane(APTES)-HAuCl4 and their subsequent transformation into stable APTES bilayer-capped gold nanoparticles through a thermal process. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:6133-6135. [PMID: 20356097 DOI: 10.1021/la100646e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In this letter, we demonstrate for the first time the electrostatically driven assembly of (3-aminopropyl)triethoxysilane (APTES) and HAuCl(4) in aqueous media into novel micrometer-scale supramolecular sheets and their subsequent transformation into small, stable APTES bilayer-capped gold nanoparticles through a thermal process. The nanoparticle formation mechanism is also discussed.
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Affiliation(s)
- Xuping Sun
- State Key Lab of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, PR China.
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340
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Hupka L, Nalaskowski J, Miller JD. Interaction forces for symmetric hydrophilic and hydrophobic systems in aqueous isopropanol solutions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:2200-2208. [PMID: 20063871 DOI: 10.1021/la903906b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Interaction force measurements were performed for a silica-silica hydrophilic system and for a silanated silica-silanated silica hydrophobic system using the atomic force microscopy colloidal probe technique. The influence of the solution composition on interaction forces was investigated. The hydrophilic silica-silica interactions were found to be described as a typical Derjaguin-Landau-Verwey-Overbeek (DLVO) system in solutions of various compositions, whereas silanated silica-silanated silica interactions were dominated by a long-range hydrophobic force. An increase in the isopropyl alcohol content of the solution diminishes both the repulsive forces in the case of the hydrophilic system and the attractive interactions in the case of the hydrophobic system.
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Affiliation(s)
- Lukasz Hupka
- Department of Metallurgical Engineering, University of Utah, Salt Lake City, UT, USA.
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341
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Kim J, Cho J, Seidler PM, Kurland NE, Yadavalli VK. Investigations of chemical modifications of amino-terminated organic films on silicon substrates and controlled protein immobilization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:2599-608. [PMID: 20095550 DOI: 10.1021/la904027p] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Fourier transform infrared spectroscopy by grazing-angle attenuated total reflection (FTIR-GATR), ellipsometry, atomic force microscopy (AFM), UV-visible spectroscopy, and fluorescence microscopy were employed to investigate chemical modifications of amino-terminated organic thin films on silicon substrates, protein immobilization, and the biological activity and hydrolytic stability of immobilized proteins. Amino-terminated organic films were prepared on silicon wafers by self-assembling 3-aminopropyltriethoxysilane (APTES) in anhydrous toluene. Surface amino groups were derivatized into three different linkers: N-hydroxysuccinimide (NHS) ester, hydrazide, and maleimide ester groups. UV-visible absorption measurements and fluorescence microscopy revealed that more than 40% of surface amino groups were chemically modified. Protein immobilization was carried out on modified APTES films containing these linkers via coupling with primary amines (-NH(2)) in intact monoclonal rabbit immunoglobulin G (IgG), the aldehyde (-CHO) of an oxidized carbohydrate residue in IgG, or the sulfhydryl (-SH) of fragmented half-IgG, respectively. FTIR spectra contain vibrational signatures of these functional groups present in modified APTES films and immobilized IgGs. Changes in the APTES film thickness after chemical modifications and protein immobilization were also observed by ellipsometric measurements. The biological activity and long-term hydrolytic stability of immobilized IgGs on modified APTES films were estimated by fluorescence measurements of an adsorbed antigen, fluorescein isothiocyanate (FITC)-labeled goat anti-rabbit IgG (FITC-Ab). Our results indicate that the FITC-Ab binding capacity of half-IgG immobilized via maleimide groups is greater than that of the oxidized IgG and the intact IgG immobilized via hydrazide and NHS ester groups, respectively. In addition, IgGs immobilized using all coupling chemistries were hydrolytically stable in phosphate-buffered saline (PBS).
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Affiliation(s)
- Joonyeong Kim
- Department of Chemistry, Buffalo State, State University of New York, 1300 Elmwood Avenue, Buffalo, New York 14222, USA.
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342
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Loscutoff PW, Zhou H, Clendenning SB, Bent SF. Formation of organic nanoscale laminates and blends by molecular layer deposition. ACS NANO 2010; 4:331-41. [PMID: 20000603 DOI: 10.1021/nn901013r] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Nanoscale organic films are important for many applications. We report on a system of molecular layer deposition that allows for the deposition of conformal organic films with thickness and composition control at the subnanometer length scale. Nanoscale polyurea films are grown on silica substrates in a layer-by-layer fashion by dosing 1,4-phenylene diisocyanate (PDIC) and ethylenediamine (ED) in the gas phase. Ellipsometry measurements indicate that the film growth occurs at a constant growth rate, with film thicknesses consistent with molecular distances calculated using density functional theory. Characterization of the films by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy reveals formation of stable polyurea films with nearly stoichiometric composition, and transmission electron microscopy indicates that the films uniformly coat the substrate surface. Subnanometer control over the film composition was demonstrated using 2,2'-thiobis(ethylamine) (TBEA) as an alternate diamine to vary the composition of the films. By substituting TBEA for ED, blended films, with homogeneous composition through the film, and nanolaminates, with discrete layers of differing film chemistry, were created.
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Affiliation(s)
- Paul W Loscutoff
- Department of Chemical Engineering, Stanford University, Hillsboro, Oregon, USA
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343
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Gomopoulos N, Saini G, Efremov M, Nealey PF, Nelson K, Fytas G. Nondestructive Probing of Mechanical Anisotropy in Polyimide Films on Nanoscale. Macromolecules 2010. [DOI: 10.1021/ma902509y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- N. Gomopoulos
- Max Planck Institute for Polymer Research Ackermannweg 10, 55128 Mainz, Germany
| | | | - M. Efremov
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Wisconsin 53706
| | - P. F. Nealey
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Wisconsin 53706
| | | | - G. Fytas
- Max Planck Institute for Polymer Research Ackermannweg 10, 55128 Mainz, Germany
- Department of Materials Science and Engineering
- Department of Materials Science University of Crete and F.O.R.T.H 77110, Heraklion, Greece
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344
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Aptekar JW, Cassidy MC, Johnson AC, Barton RA, Lee M, Ogier AC, Vo C, Anahtar MN, Ren Y, Bhatia SN, Ramanathan C, Cory DG, Hill AL, Mair RW, Rosen MS, Walsworth RL, Marcus CM. Silicon nanoparticles as hyperpolarized magnetic resonance imaging agents. ACS NANO 2009; 3:4003-8. [PMID: 19950973 PMCID: PMC4083556 DOI: 10.1021/nn900996p] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Magnetic resonance imaging of hyperpolarized nuclei provides high image contrast with little or no background signal. To date, in vivo applications of prehyperpolarized materials have been limited by relatively short nuclear spin relaxation times. Here, we investigate silicon nanoparticles as a new type of hyperpolarized magnetic resonance imaging agent. Nuclear spin relaxation times for a variety of Si nanoparticles are found to be remarkably long, ranging from many minutes to hours at room temperature, allowing hyperpolarized nanoparticles to be transported, administered, and imaged on practical time scales. Additionally, we demonstrate that Si nanoparticles can be surface functionalized using techniques common to other biologically targeted nanoparticle systems. These results suggest that Si nanoparticles can be used as a targetable, hyperpolarized magnetic resonance imaging agent with a large range of potential applications.
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Affiliation(s)
- Jacob W. Aptekar
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Maja C. Cassidy
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | - Robert A. Barton
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Menyoung Lee
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Alexander C. Ogier
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Chinh Vo
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Melis N. Anahtar
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology E19-502D Cambridge, MA 02139, USA
| | - Yin Ren
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology E19-502D Cambridge, MA 02139, USA
| | - Sangeeta N. Bhatia
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology E19-502D Cambridge, MA 02139, USA
- Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Division of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Chandrasekhar Ramanathan
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David G. Cory
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alison L. Hill
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 59, Cambridge, MA 02138, USA
| | - Ross W. Mair
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 59, Cambridge, MA 02138, USA
| | - Matthew S. Rosen
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 59, Cambridge, MA 02138, USA
| | - Ronald L. Walsworth
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 59, Cambridge, MA 02138, USA
| | - Charles M. Marcus
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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345
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Lemieux MC, Sok S, Roberts ME, Opatkiewicz JP, Liu D, Barman SN, Patil N, Mitra S, Bao Z. Solution assembly of organized carbon nanotube networks for thin-film transistors. ACS NANO 2009; 3:4089-4097. [PMID: 19924882 DOI: 10.1021/nn900827v] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ultrathin, transparent electronic materials consisting of solution-assembled nanomaterials that are directly integrated as thin-film transistors or conductive sheets may enable many new device structures. Applications ranging from disposable autonomous sensors to flexible, large-area displays and solar cells can dramatically expand the electronics market. With a practical, reliable method for controlling their electronic properties through solution assembly, submonolayer films of aligned single-walled carbon nanotubes (SWNTs) may provide a promising alternative for large-area, flexible electronics. Here, we report SWNT network TFTs (SWNTntTFTs) deposited from solution with controllable topology, on/off ratios averaging greater than 10(5), and an apparent mobility averaging 2 cm(2)/V.s, without any pre- or postprocessing steps. We employ a spin-assembly technique that results in chirality enrichment along with tunable alignment and density of the SWNTs by balancing the hydrodynamic force (spin rate) with the surface interaction force controlled by a chemically functionalized interface. This directed nanoscale assembly results in enriched semiconducting nanotubes yielding excellent TFT characteristics, which is corroborated with mu-Raman spectroscopy. Importantly, insight into the electronic properties of these SWNT networks as a function of topology is obtained.
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Affiliation(s)
- Melburne C Lemieux
- Department of Chemical Engineering, Stanford University, Stauffer III, Stanford, CA 94305-5025, USA
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346
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Byun KE, Heo K, Shim S, Choi HJ, Hong S. Functionalization of silicon nanowires with actomyosin motor protein for bioinspired nanomechanical applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2009; 5:2659-2664. [PMID: 19771569 DOI: 10.1002/smll.200900964] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- Kyung-Eun Byun
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
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347
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Rébiscoul D, Perrut V, Renault O, Rieutord F, Olivier S, Haumesser PH. Alkoxysilane layers deposited by SC CO2 process on silicon oxide for microelectronics applications. J Supercrit Fluids 2009. [DOI: 10.1016/j.supflu.2009.08.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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348
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Golas A, Parhi P, Dimachkie ZO, Siedlecki CA, Vogler EA. Surface-energy dependent contact activation of blood factor XII. Biomaterials 2009; 31:1068-79. [PMID: 19892397 DOI: 10.1016/j.biomaterials.2009.10.039] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 10/15/2009] [Indexed: 10/20/2022]
Abstract
Contact activation of blood factor XII (FXII, Hageman factor) in neat-buffer solution exhibits a parabolic profile when scaled as a function of silanized-glass-particle activator surface energy (measured as advancing water adhesion tension tau(a)(o)=gamma(lv)(o)cos theta in dyne/cm, where gamma(lv)(o) is water interfacial tension in dyne/cm and theta is the advancing contact angle). Nearly equal activation is observed at the extremes of activator water-wetting properties -36<tau(a)(o)<72 dyne/cm (0 degrees <or=theta<120 degrees), falling sharply through a broad minimum within the 20<tau(a)(o)<40 dyne/cm (55 degrees <theta<75 degrees) range over which activation yield (putatively FXIIa) rises just above detection limits. Activation is very rapid upon contact with all activators tested and did not significantly vary over 30 min of continuous FXII-procoagulant contact. Results suggest that materials falling within the 20<tau(a)(o)<40 dyne/cm surface-energy range should exhibit minimal activation of blood-plasma coagulation through the intrinsic pathway. Surface chemistries falling within this range are, however, a perplexingly difficult target for surface engineering because of the critical balance that must be struck between hydrophobicity and hydrophilicity. Results are interpreted within the context of blood plasma coagulation and the role of water and proteins at procoagulant surfaces.
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Affiliation(s)
- Avantika Golas
- Department of Bioengineering, The Pennsylvania State University, University Park, PA 16802, USA
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349
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Usrey ML, Strano MS. Adsorption of single walled carbon nanotubes onto silicon oxide surface gradients of 3-aminopropyltri(ethoxysilane) described by polymer adsorption theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:9922-9930. [PMID: 19705888 DOI: 10.1021/la901078u] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Integration of single-walled carbon nanotubes (SWNT) into complex sensing and electronic devices can necessitate the selective placement of individual nanotubes from solution onto custom-prepared surfaces. Existing studies indicate carbon nanotube adsorption can be controlled by creating hydrophilic and/or hydrophobic surfaces, depending on the nanotube surface chemistry and solvent. Various recipes exist for specific conditions, but no quantitative theoretical model describing experimental observations has been developed. This work examines the adsorption behavior of SWNT functionalized with aryl hydroxyl (OH-SWNT) or aryl carboxylic acid groups (COOH-SWNT) onto 3-aminopropyltri(ethoxysilane) (APTES) concentration gradients on SiO(2) wafers. For the first time, self-consistent field polymer adsorption theory is utilized to quantitatively describe SWNT adsorption onto planar surfaces. Experimental results indicate SWNT adsorption strongly depends on three key factors: concentration of APTES molecules on the silicon oxide and the type and number of SWNT functional groups. In general, COOH-SWNT adsorb to the greatest extent, followed by OH-SWNT and P2-SWNT. The data show a distinct threshold phenomenon, with appreciable adsorption detected only when the APTES concentration exceeded 2.6 x 10(14) molecules/cm(2).
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Affiliation(s)
- Monica L Usrey
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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350
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One-step and high-density protein immobilization on epoxysilane-modified silica nanoparticles. Sci Bull (Beijing) 2009. [DOI: 10.1007/s11434-009-0210-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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