Electrochemical sensing of guanine, adenine and 8- hydroxy-20-deoxyguanosine at glassy carbon modified with single-walled carbon nanotubes covalently functionalized with lysine

ALEJANDRO GUTIERREZ,; FABIANA A. GUTIERREZ; MARCOS EGUILAZ; JOSE M. GONZALEZ- DOMINGUEZ; JAVIER HERNANDEZ-FERRER,; ALEJANDRO ANSON-CASAOS; MA T. MARTINEZ; GUSTAVO A. RIVAS

RSC Advances

Royal Society of Chemistry

Año: 2016 vol. 6 p. 13469 - 13477

This work reports the synthesis and characterization of single-walled carbon nanotubes (SWCNT)covalently functionalized with L-lysine (Lys) and the analytical performance of glassy carbon electrodes(GCE) modified with a dispersion of SWCNT-Lys (GCE/SWCNT-Lys) for the highly sensitive quantificationof guanine, adenine and 8-hydroxy-20-deoxyguanosine. Detection limits of 75, 195 and 97 nM wereobtained for guanine, adenine and 8-hydroxy-20-deoxyguanosine, respectively by voltammetricadsorptive stripping with medium exchange. GCE/SWCNT-Lys was successfully used for the detection ofadenine and guanine oxidation after adsorption of salmon sperm-double stranded DNA. A cleardefinition of 8-hydroxy-20-deoxyguanosine oxidation signal is observed even in the presence of largeexcess of guanine, adenine or salmon sperm-double stranded DNA.