Radiolytic introduction of multiple functional groups to multiwalled carbon nanotubes and their application as biosensor supports



Tyrosinase was immobilized on multiwalled carbon nanotube (MWNT) supports that were functionalized with multiple groups. It was then used for the detection of phenolic compounds. The radiation-induced graft polymerization of 1-[(4-ethenylphenyl)methyl]-3-buthyl-imidazolium chloride and vinyl ferrocene introduced functional groups derived from both species onto the nanotubes' surfaces: imidazolium salts that contained sites for the enzyme's immobilization via ionic bonding and ferrocene compounds that acted as electron transfer mediators via redox reactions. Using these additives at a 1 : 4 molar ratio resulted in an electrode with optimized current. The multifunctionalized nanotube supports were characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, and thermogravimetric analysis. The prepared tyrosinase-immobilized biosensor showed a sensing range of 1.0 × 10−4 M to 7.0 × 10−4 M and was used for the detection of phenolic compounds in red wines. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013