The HM coating constitutes, to some extent, an effective surface engineering technique in a neutral environment, as it allows maintenance of a stable redox peak potential under pH fluctuations. HM presence limits hydronium ions' activity at the reaction plane. Discussing the pH effect, one must consider that the hydrogel layer thickness surpasses the diffusion layer thickness, thus leading to an assumption that the bulk electrolyte pH and concentration may not reflect the conditions within the hydrogel layer.