New self-assembled layers composed with gold nanoparticles, cysteamine and dihydrolipoic acid deposited on bare gold template for highly sensitive and selective simultaneous sensing of dopamine in the presence of interfering ascorbic and uric acids

A gold bare template modified with self-assembled layers (SAMs) composed of gold nanoparticles and organic S-containing compound: cysteamine and dihydrolipoic acid were prepared. The electrode with SAMs endowed with gold nanoparticles gave a high catalytic effect for dopamine electrooxidation alone and in the presence of biogenic interfering compounds: ascorbic acid and uric acid in solution at pH 7. For this novel sensor, a linear relationship between the current response of dopamine at the potential of peak maximum (j (p)) and the concentration of this compound in solution (c (DA)) was found over the range 0.1 mu M to 0.85 mM with the detection limit of 0.023 mu M.