In fact, current response increased with 1,2-benzoquinone concentration and gelatin layer permeability. The latter was dependent on the concentration of the gelatin solution, and on the thickness of the hydrogel film, determined by the volume of the deposited gelatin solution. Lesser the gelatin solution concentration and the volume of the deposited drop, higher the layer permeability. Taking into account these effects, further experiments were performed in the following optimal experimental conditions: gelatin solution concentration 6% and volume of 8 L of the gelatin solution deposited onto the electrode surface, allowing reaching a maximal current response for an analyte concentration of 5 mM