Dawson-Type Vanadium-Substituted Tungstophosphate- Modified ITO Electrode: Preparation, Characterization and Electrochemical Determination of Dopamine

摘要

In this work, we describe a robust composite film-modified indium tin oxide (ITO) electrode withimproved detection capabilities for an example neurotransmitter, dopamine (DA). The composite filmwas developed by the combination of a Dawson-type vanadium tungstophosphate, α 2 -K 7 P 2 W 17 VO 62 ·18H 2 O (P 2 W 17 V), and cationic chitosan (CS) via a layer-by-layer (LbL) self-assemblytechnique. The composite film-modified electrode presents excellent electrochemical catalytic activitytowards dopamine (DA) with a linear response over the range of 1.25 × 10 –8 M to 3.04 × 10 -4 M. Theproposed system responds selectively to dopamine with a low detection limit of 0.18 μM (S/N = 3), ahigh sensitivity of 0.23 μA μM -1 and a quick response time. As a result, the prepared composite filmmaterials with these superior properties show promising applicability in electrochemical sensors.