Dawson-type vanadium-substituted tungstophosphate-modified ITO electrode: Preparation, characterization and electrochemical determination of dopamine

Abstract

In this work, we describe a robust composite film-modified indium tin oxide (ITO) electrode with improved detection capabilities for an example neurotransmitter, dopamine (DA). The composite film was developed by the combination of a Dawson-type vanadium tungstophosphate, α 2 -K 7 P 2 W 17 VO 62 ·18H 2 O (P2W17V), and cationic chitosan (CS) via a layer-by-layer (LbL) self-assembly technique. The composite film-modified electrode presents excellent electrochemical catalytic activity towards dopamine (DA) with a linear response over the range of 1.25 × 10 -8 M to 3.04 × 10 -4 M. The proposed system responds selectively to dopamine with a low detection limit of 0.18 μM (S/N = 3), a high sensitivity of 0.23 μA μM -1 and a quick response time. As a result, the prepared composite film materials with these superior properties show promising applicability in electrochemical sensors.