Tests of lipid peroxidation products using the DNA based electrochemical biosensor
Institute of Analytical Chemistry, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovakia
a Food Research Institute, Biocentrum, Kostolná 7, 900 01 Modra, Slovakia
Abstract: In this work screen-printed carbon electrodes (SPCE) were modified with different nanocomposites: chitosan - multi-walled carbon nanotubes (CHIT-MWNT/SPCE), chitosan - single-walled carbon nanotubes (CHIT-SWNT/SPCE) and chitosan - carboxylated single-walled carbon nanotubes (CHIT-SWNT-COOH/SPCE) and further modified with DNA. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize basic electrochemical properties of the prepared sensors and biosensors. For the lipid peroxidation tests, DNA was first incubated with malondialdehyde (MDA) and oxidized edible oils, then isolated and put onto the surface of CHIT-SWNT-COOH/SPCE. Adducts formation of MDA and lipid peroxidation products with DNA was found. These adducts inhibit the diffusion of the electrochemical probe [Fe(CN)6]3−/4− to the electrode surface and, thus, changes in the relative charge-tranfer resistance were observed. These changes are in good agreement with the amount of lipid peroxidation products determined by the peroxide and TBARS values.
Keywords: DNA biosensor, lipid peroxidation, screen-printed carbon electrode, chitosan, carbon nanotubes, edible oils
Full paper in Portable Document Format: acs_0006.pdf
Acta Chimica Slovaca, Vol. 1, No. 1, 2008, pp. 58—71