Hybrid electrochemical sensor platform for capsaicin determination using coarsely stepped cyclic squarewave voltammetry

Abstract A small, standalone electrochemical hybrid sensor platform, combining flexible electronics and screen-printed electrodes, is demonstrated in the determination of capsaicin through adsorptive stripping voltammetry. The sensing scheme was simplified to be compatible with a low-cost device. The simplification involved eliminating the need for additional modification of the electrode and employing a coarsely stepped squarewave voltammetry, a technique which is applicable with less sophisticated instrumentation. This architecture was found to be suitable for concentrations up to at least 5000 µM with a detection limit of 1.98 µM. The screen-printed carbon graphite electrodes were made reusable through an ethanol rinsing protocol. The effect of ethanol/buffer volumetric ratio in the test sample was shown to greatly influence the analytical data, and a fixed 10% (v/v) was chosen as a compromise between signal-to-noise ratio and not exceeding the solubility limit of the desired upper range.