The continuous search for new sensing materials with high recognition capabilities is necessary to improve existing analytical procedures and to develop new ones. Natural glassy carbon and polydimethylsiloxane were shown to be used for the preparation of carbon paste electrodes to employ them in new, voltammetric, green-chemistry-friendly electroanalytical procedures aimed at evaluating the antioxidant capacity of plant extracts, dietary supplements, and hydrolats. The developed electrodes provided well-shaped and reproducible voltammetric signals (RSD = 1%) of the oxidation of epigallocatechin gallate, the main component of many plants and plant-based formulations with antioxidative activity, in the 1–12.5 µM range (DPV mode, LOD = 0.08 µM). If needed, the performance of new carbon paste electrodes can be further enhanced by the introduction of trivalent rare earth oxides to carbon paste to increase its active surface, facilitate electron transfer, and improve the resolution of recorded signals.

A virtual experiment conducted using the ICP-MS TuneSim software served as the basis for studies that compared the applicability of the central composite design with the Box–Behnken design in analytical chemistry applications. The insights gathered from these virtual experiments were used in real-life electroanalytical tests, including the determination of germanium and the studies of the antioxidant properties of herbal infusions. The experimental design and interpretation of the results were performed using Statistica software.