Hamed Najari

Hamed Najari, Ph.D.

Project

Specific and sensitive optical detection by recognition of DNA with Cationic Polythiophenes on solid support.

Recently, intense research has been carried out worldwide with the goal of developing sensitive and specific detection tools for biomedical research applications. Most of the current methods for the detection of DNA are based on an enzymatic amplification (Polymerase Chain Reaction or PCR) of the targets. In most cases, PCR is a powerful technique but shows some disadvantages; such an easy contamination of the reactional medium which implies false positive results. By combining soluble cationic polythiophenes and optical amplification tools, we try to detect genetic materials on to solid supports without using the PCR technology. Detection on solid substrate presents the main advantage of being able to study the behaviour of many genes simultaneously. Our method is based on hybrid DNA/polythiophene electrostatic complexes. Detection of DNA on the functionalized glass substrate is carried out in several steps: first, single stranded DNA capture probes and polymer are grafted on amine modified slide surfaces; then, the target DNA can hybridize. Specific detection of target DNA is performed by using a combination of a cationic polythiophene and Cy3 labeled DNA probes.

Readings are performed with a commercial microarray fluorescence scanner at the following wavelength, 408 nm or 540 nm (excitation) and 570 nm (emission). We try to demonstrate that it is possible to detect specifically and sensitively target DNA on solid support by using a cationic polythiophene as transducer of the double helix.

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Business Address

Université Laval, Département de Chimie, Pavillon Alexandre-Vachon,
1045 Av. de la médecine, Bureau 2412, Québec, Qc, Canada G1V 0A6

P : (418) 656-2131 # 6555  |  E : hamed.najari.1@ulaval.ca

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Education

Postdoctoral Fellow Université Laval
2004-
Ph.D. Chemistry Université Paris VII Denis Diderot
1998-2003
M. Sc. Chemistry Université Paris Sud Orsay
1995-1997
B. Sc. Chemistry Université Paris XII, Créteil
1992-1995

Bilingual: French (first language), English (second language) Arab (second langue), Spanish (some notion).

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Scientific Knowledge

Characterization Techniques

  • Spectroscopy: FTIR (IRAS, PM-IRAS), UV-Vis, Fluorescence, HREELS, EXAFS
  • Electrochemistry: CV
  • Surface: XPS, Ellipsometry, contact angle, AFM, STM, MEB
  • Other: pulse radiolysis

General Knowledge

Characterization of physico-chemistry properties of conjugated polymers by different techniques of analyses. Fabrication and characterization of monolayer on metallic support. High vacuum deposition of small molecules and metals. Spin coating of polymers solution.

Softwares

Microsoft Office, Origin, ChemDraw, HyperChem, Nanoscope, EndNote, Adobe Acrobat, Adobe Photoshop, blender, Omnic.
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Positions Held

Postdoctoral fellow in Chemistry
Department of Chemistry, Université Laval | 2004 – present

  • Project Leader: Determination of DNA detection on solid support, characterisation of surfaces.
  • Development of fluorescence DNA detection by using a polymer
  • Characterisation of solid support (glass-plastic) in the DNA detection.
  • Development of new surface fonctionalization  
  • Supervision of undergraduates students
  • Preparation of scientific papers, multimedia presentations, seminars, abstracts, posters and conferences for national and international symposium.
  • Resolution of problems leads to the DNA detection in group meeting.

Ph.D. Student and Researcher
Department of Chemistry, Université Paris VII Denis Diderot | 1998 – 2003

  • Characterisation of zinc surface by using a organosilane as coupling agent
  • Development of monolayer system in order to improve the polyisopren epoxidized adherence.
  • Characterisation of monolayer on metallic solid support. Grafting of self-assembled monolayer.
  • Development of adherence by using monolayers
  • Supervision of undergraduates students
  • Preparation of scientific papers, multimedia presentations, seminars, abstracts, posters and conferences for national and international symposium.
  • Resolution of problems leads to the adherence system in group meeting.

M. Sc. Student and Researcher
Department of Chemistry, Université Paris Sud Orsay | 1995 – 1997

  • Modification of metallic surfaces by using monolayer monomolecular of oligothiophenes functionalized by thiols.
  • Characterisation of monomolecular monolayer of thiols on gold and silver surfaces
  • Preparation of scientific papers, multimedia presentations
  • Resolution of problems leads to the monolayer system in group meeting.

Teaching Assistant
Department of Chemistry, Université Laval

Chemistry-Physics | 2007 – 2008
Formation and supervision of undergraduate’s students during their period stage.

Teaching Assistant
Department of Chemistry, Université Paris VII

Chemistry-Physics | 2000 – 2003
Formation and supervision of undergraduate’s students during their period stage.

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Scholarship And Awards

European and industrial
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Publications

7. Structural investigation for the Aminopropyltrimethoxysilane (APS) and Mercaptopropyltrimethoxysilane (g-MPS) films Deposited onto zinc.
A. Najari, P. Lang, D. Mauer, F. Garnier. (En cours de publication).

6. A new organofonctional methoxysilane bilayer system for promoting adhesion of epoxydized rubber to zinc. Part 1 : Optimization of pratical adhesion. A. Najari., P. Lang., P-C. Lacaze, D. Mauer. Soumis à Chemical Material.

5. Optical detection of DNA and proteins moth cationic polythiophenes.
H. A. Ho., A. Najari,. M. Leclerc. Acc. Chem. Res., 2008, 41, 168.

4. Protein Detecting Arrays Based on Cationic Polythiophene-DNA-Aptamer Complexes M. Béra Abérem, A. Najari, H.-A. Ho, J.-F. Gravel, P. Nobert, D. Boudreau, M. Leclerc. Adv. Mater. 2006, 18, 2703-2707

3. Reagentless Ultrasensitive Specific DNA Array Detection Based on Responsive Polymeric Biochips. A. Najari, H. A. Ho, J. F. Gravel, Ph. Nobert, D. Boudreau, M. Leclerc. Anal. Chem. 78 (22), 7896 -7899, 2006.

2. b-fonctionalized oligothiophene for molecular self-assembly.
R. Michalitsch, C. Nogues, A. Najari, A. El Kassmi, A. Yassar,. Synthetic Metal, 1999, 101, 5-6.

1. Self assembled monolayers based on a-functionalized quaterthiophene
R. michalitschc C. Nogues, A. Najari, A. El Kassmi, A. Yassar, P. Lang, R. Vilar, F. Garnier. Synthetic Metal. 1999, 102, 1319.
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Proceedings

  • Advanced Materials vol 18, n°20 October 17, 2006.
  • Macromolecular Rapid Communications vol 28, n°17 September 3, 2007.
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Conferences

2. A. Najari, Juin  2001. Adhésion d’un polybutadiene sur substrat de zinc via l’utilisation d’agents de couplages de type organosilane, Séminaire de Doctorat, Bekaert, Zwevegem, Belgique

1. D. Mauer, A. Najari, P. Lang, F. Garnier. New adhesion systems for bonding zinc coated cords to rubber.3rd Rubber Bonding Conference Amsterdam, The Netherlands 15th – 16th May 2000.
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Poster Presentations

3. A .Najari, H. A. Ho., M. Leclerc, Specific and sensitive optical detection by double recognition of DNA with Cationic Polythiophenes on solid support. Detection Technologie San-Diego 1-2 Nov 2007

2. A .Najari, H. A. Ho., M. Leclerc; DNA Arrays: selective, ultrasensitive and simple detection of DNA on responsive solid supports. International Conference on Synthetic Metals (ICSM 06). Dublin 02-07 juillet 2006.

1. A .Najari, H. A. Ho., M. Leclerc. Greffage de Monocouche d’ADN Fonctionnalisée sur une Surface de Verre.. Congrès annuel du CERSIM.  Université Laval, Québec Canada. mars 2005.
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