Amperometric Detection and Quantification of 8-Hydroxy-2′-deoxyguanosine (8-OHdG) Using Dendrimer Modified Electrodes

8-Hydroxy-2'-deoxyguanosine (8-OHdG) detection by high performance liquid chromatography (HPLC) with amperometric detection was studied using a Au electrode modified with different dendrimer based thin films. Gold electrode is thiol-modified, forming self-assembled monolayers on which different generation PAMAM dendrimers with terminal functional groups -COOH and -NH2 have been attached using peptidic bonds. Results obtained in synthetic samples show low limits of detection and quantification for 8-OHdG (1.2 x 10(-9) and 3.7 x 10(-9) M respectively), with matrix interference elimination, thus avoiding sample pretreatment. Best results are obtained with electrodes modified with aliphatic amino thiols and 3.5 and 4.5 generation carboxylated dendrimers (Au/AET/DG(3.5) and Au/AET/DG(4.5)), demonstrating that these materials constitute a good alternative for 8-OHdG determination in biological fluids.