title: E-DNA sensor of Mycobacterium tuberculosis based on electrochemical assembly of nanomaterials (MWCNTs/PPy/PAMAM).
abstract: Two-step electrochemical patterning methods have been employed to elaborate composite nanomaterials formed with multiwalled carbon nanotubes (MWCNTs) coated with polypyrrole (PPy) and redox PAMAM dendrimers. The nanomaterial has been demonstrated as a molecular transducer for electrochemical DNA detection. The nanocomposite MWCNTs-PPy has been formed by wrapping the PPy film on MWCNTs during electrochemical polymerization of pyrrole on the gold electrode. The MWCNTs-PPy layer was modified with PAMAM dendrimers of fourth generation (PAMAM G4) with covalent bonding by electro-oxidation method. Ferrocenyl groups were then attached to the surface as a redox marker. The electrochemical properties of the nanomaterial (MWCNTs-PPy-PAMAM-Fc) were studied using both square wave voltammetry and cyclic voltammetry to demonstrate efficient electron transfer. The nanomaterial shows high performance in the electrochemical detection of DNA hybridization leading to a variation in the electrochemical signal of ferrocene with a detection limit of 0.3 fM. Furthermore, the biosensor demonstrates ability for sensing DNA of rpoB gene of Mycobacterium tuberculosis in real PCR samples. Developed biosensor was suitable for detection of sequences with a single nucleotide polymorphism (SNP) T (TCG/TTG), responsible for resistance of M. tuberculosis to rifampicin drug, and discriminating them from wild-type samples without such mutation. This shows potential of such systems for further application in pathogens diagnostic and therapeutic purpose.
authors: CNRS UMR-8182, Institut de Chimie Moléculaire et de Matériaux d'Orsay, Equipe de Chimie Bioorganique et Bioinorganique, Université Paris-Sud , Bâtiment 420, 91405 Orsay, France.
authors: Anna
authors: A
authors: Miodek
authors: CNRS UMR-8182, Institut de Chimie Moléculaire et de Matériaux d'Orsay, Equipe de Chimie Bioorganique et Bioinorganique, Université Paris-Sud , Bâtiment 420, 91405 Orsay, France.
authors: Nawel
authors: N
authors: Mejri
authors: Institut of Integrative Cell Biology, Orsay, CEA-CNRS-Université Paris-Sud , UMR9198, Bâtiment 400, 91405 Orsay, France.
authors: Michel
authors: M
authors: Gomgnimbou
authors: Institut of Integrative Cell Biology, Orsay, CEA-CNRS-Université Paris-Sud , UMR9198, Bâtiment 400, 91405 Orsay, France.
authors: Christophe
authors: C
authors: Sola
authors: CNRS UMR-8182, Institut de Chimie Moléculaire et de Matériaux d'Orsay, Equipe de Chimie Bioorganique et Bioinorganique, Université Paris-Sud , Bâtiment 420, 91405 Orsay, France.
authors: Hafsa
authors: H
authors: Korri-Youssoufi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D050091:Dendrimers / Q000737:chemistry*; D004563:Electrochemistry; D004579:Electron Transport; D006046:Gold / Q000737:chemistry; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D053761:Nanocomposites / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D004277:DNA, Single-Stranded; D050091:Dendrimers; D037742:Nanotubes, Carbon; C104700:PAMAM Starburst; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D006046:Gold; D004247:DNA