Covalent modification of carbon nanotubes with anthraquinone by electrochemical grafting and solid phase synthesis

Anthraquinone groups were covalently attached to carbon nanotubes (CNTs) through either benzyl amine (C6H4CH2NH) or ethylenediamine (EDA) linkers using a combination of electrochemical surface modification and solid-phase synthetic methodology. Following abrasive or wet casting immobilization of multiwall CNTs onto glassy carbon substrates, the linker groups were covalently grafted to the CNTs either by electrochemical reduction of C6H4CH2NHBoc diazonium salt or oxidation of Boc-EDA. The Boc group was then removed and the anthraquinone groups attached to the linker by amide coupling using solid-phase synthesis methods. The surface coverage, stability, affect of pH and buffer capacity of the tethered anthraquinone groups was investigated by cyclic voltammetry. The modification procedure is also performed using polished GC for comparison with modified CNTs