| Authors | Fariba Dashtestani, Hedayatollah Ghourchian, Khadijeh Eskandari, Hossain Ali Rafiee Pour |
|---|---|
| Journal | Microchemica Acta |
| Page number | 1045–1053 |
| Volume number | 182 |
| Paper Type | Full Paper |
| Published At | 2014 |
| Journal Grade | ISI |
| Journal Type | Typographic |
| Journal Country | Austria |
Abstract
A nanocomposite consisting of gold nanoparticles and the copper(II) complex of cysteine (GNP/Cu-Cys) is shown to represent a useful mimic for the enzyme superoxide dismutase (SOD). The relative activities of plain GNPs, Cu metal, Cys, Cu-Cys and GNP/Cu-Cys were determined and compared to those of native SOD. The value for half-maximal inhibitory concentration of the nanocomposite is 0.3 μg mL‾1 which is 3 times higher than that of the native enzyme. The GNPs/Cu-Cys nanocomposite was immobilized on a carbon paste electrode and used as a biomimetic sensor for the detection of superoxide anions. The resulting sensor has a linear range over the concentration range from 3.1 to 326 μM, a detection limit of 2.8 μM (at an S/N of 3), and a sensitivity of 0.018 μA μM.cm−2. The selectivity for superoxide anions over potential interferents such as hydrogen peroxide, uric acid and citric acid is excellent.