TY - GEN A1 - Kurniawan, Fredy A1 - Tsakova, Vessela T. A1 - Mirsky, Vladimir M. T1 - Analytical applications of electrodes modified by gold nanoparticles: dopamine detection T2 - Journal of Nanoscience and Nanotechnology N2 - Dopamine oxidation was studied on modified gold (nano-Au) electrodes obtained by Layer-by-Layer deposition of gold nanoparticles and polyacrylic acid. A gradual loss of electrochemical activity for the dopamine oxidation reaction is observed at pH 7. Simultaneous SPR spectroscopy and cyclic voltammetry indicate the formation of an adsorbed layer on the electrode surface at this pH value. Investigations, performed through electrochemical and SPR measurements at pH 4, give evidence for a reversible process. At this pH value both dopamine oxidation and reduction current peaks show linear dependence on the dopamine concentration and may be used for analytical applications. The use of the nano-Au electrode allows resolving the peaks corresponding to ascorbic acid and to dopamine oxidation by 240 mV thus providing a high selectively for dopamine detection in the presence of ascorbic acid. The detection limit of this electrode for dopamine is below 4 microM in the presence of 1 mM ascorbic acid. The sensitivity normalized to the macroscopic electrode surface is about 10 mA cm(-2) mM(-1) at sweep rate of 10 V/s. KW - ascorbic acid KW - dopamine KW - electrochemical detection KW - gold nanoparticles KW - surface plasmon resonance Y1 - 2016 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/17823 SN - 1533-4880 SN - 1533-4899 VL - 9 IS - 4 SP - 2407 EP - 2412 ER -