self-assembled monolayers of organosulfur derivative on gold nanoparticles as electrochemical sensor for determination of isoprenaline

In this paper, the use of molecular self-assembled monolayers of 5-(1,3-dithiolan-2-eyl)-3-methyl banzen-1,2-diol (dmd) on gold nanoparticles was described (dmd-aunps). the redox properties of modified electrode at various scan rates were investigated by cyclic voltammetry. a pair of well-defined quasi-reversible redox peaks of dmd were obtained at the modified electrode. dramatically enhanced electrocatalytic activity was exemplified at the dmd-aunps, as an electrochemical sensor to investigate the electro-oxidation of isoprenaline (ip). with this modified electrode, the oxidation potential of the ip was shifted about 235 mv toward a less positive potential value than that of an unmodified electrode. the values of electron transfer coefficients (α = 0.5), catalytic rate constant (ks = 9.2 s−1) and diffusion coefficient (d = 8.9 × 10−5 cm2 s−1) were calculated for ip. the response of catalytic current with ip concentration showed a linear relation in the range from 0.5 to 800 µm with a detection limit of 0.21 µm. finally, this modified electrode was used for the determination of ip in ip injections.