Amperometric biosensors based on biotinylated single-walled carbon nanotubes.
One challenging goal for the development of biosensors is the conception of three dimensional biostructures on electrode surfaces. In this context, single-walled carbon nanotube coatings (SWCNTs), functionalized by biotin groups, were investigated to develop 3D conductive nanostructures allowing a post-functionalization by biological macromolecules. This specific anchoring of biomolecules was carried via the affinity interactions using the avidin-biotin system. For this purpose, a biotinylated pyrene was specially synthesized to develop a non-covalent functionalization based on pi-interactions between pyrene and the nanotube sidewall. SWCNT coatings were also biotinylated via electropolymerization of biotin-pyrrole derivatives at 0.95 V in CH3CN electrolyte. The resulting biotinylated SWCNTs were modified by an avidin protein via affinity interactions and characterized with scanning electron microscopy. The biofunctionalization by a biotinylated glucose oxidase (GOX) was performed by successive incubation in avidin and GOX aqueous solutions via avidin bridges. The efficiency of the enzyme anchoring was examined through the electro-enzymatic activity of the modified electrodes towards the detection of glucose at 0.7 V versus SCE. The glucose sensitivity and maximum current density were 1.6 mAM(-1) cm(-2) and 131 microAcm(-2) respectively for pyrene biotin-SWCNT electrode and 2.5 mAM(-1) cm(-2) and 178 microAcm(-2) respectively for the poly(pyrrole biotin)-SWCNT.
Holzinger
M
M
Département de Chimie Moléculaire, UMR CNRS 5250, ICMG FR CNRS 2607, Université Joseph Fourier, BP 53, 38041 Grenoble, Cedex 9, France.
Haddad
R
R
Maaref
A
A
Cosnier
S
S
D015374:Biosensing Techniques; D001710:Biotin / Q000737:chemistry*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000378:metabolism; D013058:Mass Spectrometry; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon; D011108:Polymers / Q000737:chemistry; D011721:Pyrenes / Q000737:chemistry
D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D011108:Polymers; D011721:Pyrenes; D001710:Biotin; C030984:pyrene; D005949:Glucose Oxidase; D005947:Glucose