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Abstract
Surface modification is recognized as one of the fundamental techniques to fabricate biosensing interfaces. This review focuses on the surface modification of carbon substrates (GC and HOPG) and silica with a close-packed monolayer, in particular. In the cases of carbon substrates, GC and HOPG, it was demonstrated that surface modification of carbon substrates with diazonium derivatives could create a close-packed monolayer similar to the self-assembled monolayer (SAM) formation with mercapto derivatives. Similarly, the potential of trialkoxysilanes to form a close-packed monolayer was evaluated, and modification with a close-packed monolayer tended to occur under milder conditions when the trialkoxysilanes had a longer alkyl chain. In these studies, we synthesized surface modification materials having ferrocene as a redox active moiety to explore features of the modified surfaces by an electrochemical method using cyclic voltammetry, where surface concentrations of immobilized molecules and blocking effect were studied to obtain insight for density leading to a close-packed layer. Based on those findings, fabrication of a biosensing interface on the silica sensing chip of the waveguide-mode sensor was carried out using triethoxysilane derivatives bearing succinimide ester and oligoethylene glycol moieties to immobilize antibodies and to suppress nonspecific adsorption of proteins, respectively. The results demonstrate that the waveguide-mode sensor powered by the biosensing interface fabricated with those triethoxysilane derivatives and antibody has the potential to detect several tens ng/mL of biomarkers in human serum with unlabeled detection method.
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Affiliation(s)
- Mutsuo Tanaka
- Department of Life Science & Green Chemistry, Saitama Institute of Technology
| | - Osamu Niwa
- Advanced Science Research Laboratory, Saitama Institute of Technology
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Fakharan Z, Naji L, Madanipour K. Surface roughness regulation of reduced-graphene oxide/iodine - Based electrodes and their application in polymer solar cells. J Colloid Interface Sci 2019; 540:272-284. [PMID: 30660080 DOI: 10.1016/j.jcis.2019.01.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/20/2018] [Accepted: 01/08/2019] [Indexed: 11/30/2022]
Abstract
The current work presents an iodine-mediated fine-tuning method for the electrical and electrochemical properties of reduced-graphene oxide (r-GO)/iodine - based electrodes for application in ITO-free polymer solar cells (PSCs). A multi-technique investigation was applied to correlate the morphological features of GO thin films (GO TFs) with iodine adsorption during the reduction process by HI vapor, electrochemical band gap, Fermi potential, charge carrier mobility and charge density of iodine/r-GO based electrodes. The electrical and electrochemical characteristics of iodine/r-GO electrodes changed considerably by alteration of their surface roughness and iodine content. Iodine/r-GO TFs with the lowest surface roughness and the highest iodine content exhibited the highest charge carrier density and Fermi potential. Electrochemical impedance spectroscopy (EIS) and quantum Hall effect (QHE) results confirmed the p-type conductivity of r-GOs/iodine-based electrodes. PSCs were fabricated using r-GO/iodine electrodes as the photo-anode to follow the influences of iodine content and surface roughness on the photovoltaic performance of the cells. PSCs prepared based on r-GO/iodine electrodes possessing the lowest surface roughness and the highest iodine content provided the lowest charge transfer resistance (Rct) and remarkably higher (∼48%) PCE.
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Affiliation(s)
- Zahra Fakharan
- Department of Chemistry, AmirKabir University of Technology, 424 Hafez Avenue, Tehran P.O Box 15875-4413, Iran
| | - Leila Naji
- Department of Chemistry, AmirKabir University of Technology, 424 Hafez Avenue, Tehran P.O Box 15875-4413, Iran.
| | - Khosro Madanipour
- Optics, Laser and Photonics Research Institute, Amirkabir University of Technology, 424 Hafez Avenue, Tehran P.O Box 15875-4413, Iran
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Berisha A, Combellas C, Kanoufi F, Médard J, Decorse P, Mangeney C, Kherbouche I, Seydou M, Maurel F, Pinson J. Alkyl-Modified Gold Surfaces: Characterization of the Au-C Bond. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11264-11271. [PMID: 30173513 DOI: 10.1021/acs.langmuir.8b01584] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The surface of gold can be modified with alkyl groups through a radical crossover reaction involving alkyliodides or bromides in the presence of a sterically hindered diazonium salt. In this paper, we characterize the Au-C(alkyl) bond by surface-enhanced Raman spectroscopy (SERS); the corresponding peak appears at 387 cm-1 close to the value obtained by theoretical modeling. The Au-C(alkyl) bond energy is also calculated, it reaches -36.9 kcal mol-1 similar to that of an Au-S-alkyl bond but also of an Au-C(aryl) bond. In agreement with the similar energies of Au-C(alkyl) and Au-S-(alkyl), we demonstrate experimentally that these groups can be exchanged on the surface of gold.
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Affiliation(s)
- Avni Berisha
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
- Chemistry Department of Natural Sciences Faculty , University of Prishtina , rr. "Nëna Tereze" nr. 5 , 10000 Prishtina , Kosovo
| | - Catherine Combellas
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
| | - Frédéric Kanoufi
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
| | - Jérôme Médard
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
| | - Philippe Decorse
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
| | - Claire Mangeney
- Sorbonne Paris Cité, Université Paris Descartes, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS , 45 rue des Saints Pères , 75006 Paris , France
| | - Issam Kherbouche
- Sorbonne Paris Cité, Université Paris Descartes, Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS , 45 rue des Saints Pères , 75006 Paris , France
| | - Mahamadou Seydou
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
| | - François Maurel
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
| | - Jean Pinson
- Sorbonne Paris Cité, Université Paris Diderot, ITODYS, UMR 7086 CNRS , 15 rue J-A de Baïf , 75013 Paris , France
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Hetemi D, Kanoufi F, Combellas C, Pinson J, Podvorica FI. Electrografting of alkyl films at low driving force by diverting the reactivity of aryl radicals derived from diazonium salts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:13907-13913. [PMID: 25350951 DOI: 10.1021/la503833j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Alkyl and partial perfluoroalkyl groups are strongly attached to carbon surfaces through (i) the abstraction of the iodine atom from an iodoalkane by the sterically hindered 2,6-dimethylphenyl radical and (ii) the reaction of the ensuing alkyl radical with the carbon surface. Since the 2,6-dimethylphenyl radical is obtained at -0.25 V/Ag/AgCl by reducing the corresponding diazonium salt, the electrografting reaction is facilitated by ∼1.7 V by comparison with the direct electrografting of the iodo compounds. Layers of various thicknesses, including monolayers, are obtained by controlling the time duration of the electrolysis. The grafted films are characterized by electrochemistry, IR, XPS, ellipsometry, and water contact angles.
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Affiliation(s)
- Dardan Hetemi
- Université Paris Diderot , Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baïf, 75205 Paris Cedex 13, France
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Debela AM, Ortiz M, Beni V, O'Sullivan CK. Facile electrochemical hydrogenation and chlorination of glassy carbon to produce highly reactive and uniform surfaces for stable anchoring of thiolated molecules. Chemistry 2014; 20:7646-54. [PMID: 24829137 DOI: 10.1002/chem.201402051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Indexed: 11/11/2022]
Abstract
Carbon is a highly adaptable family of materials and is one of the most chemically stable materials known, providing a remarkable platform for the development of tunable molecular interfaces. Herein, we report a two-step process for the electrochemical hydrogenation of glassy carbon followed by either chemical or electrochemical chlorination to provide a highly reactive surface for further functionalization. The carbon surface at each stage of the process is characterized by AFM, SEM, Raman, attenuated total reflectance (ATR) FTIR, X-ray photoelectron spectroscopy (XPS), and electroanalytical techniques. Electrochemical chlorination of hydrogen-terminated surfaces is achieved in just 5 min at room temperature with hydrochloric acid, and chemical chlorination is performed with phosphorus pentachloride at 50 °C over a three-hour period. A more controlled and uniform surface is obtained using the electrochemical approach, as chemical chlorination is observed to damage the glassy carbon surface. A ferrocene-labeled alkylthiol is used as a model system to demonstrate the genericity and potential application of the highly reactive chlorinated surface formed, and the methodology is optimized. This process is then applied to thiolated DNA, and the functionality of the immobilized DNA probe is demonstrated. XPS reveals the covalent bond formed to be a C-S bond. The thermal stability of the thiolated molecules anchored on the glassy carbon is evaluated, and is found to be far superior to that on gold surfaces. This is the first report on the electrochemical hydrogenation and electrochemical chlorination of a glassy carbon surface, and this facile process can be applied to the highly stable functionalization of carbon surfaces with a plethora of diverse molecules, finding widespread applications.
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Affiliation(s)
- Ahmed M Debela
- Departament d'Enginyería Química, Universitat Rovira i Virgili, Avinguda Països Catalans, 26, 43007 Tarragona (Spain), Fax: (+34) 977559667/0034977559721
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