<p>Widespread enzymatic glucose sensor electrodes used in diabetes management could be substituted with more stable and cost-effective enzymeless electrodes due to the development of appropriate electrocatalysts for direct anodic oxidation of glucose in the isotonic neutral medium. The performance in this reaction of the electrodeposited ε-MnO₂ polymorph (akhtenskite phase) was explored for the first time using a rotating disk electrode technique. The effect of ε-MnO₂ annealing temperature in a 50 to 450&#xa0;°C range on its structural, morphological and electrochemical characteristics was also investigated. To establish an electrochemical window for the glucose detection, which is limited by ε-MnO₂ cathodic dissolution potentials and O₂/Cl₂ evolution potentials, a rotating ring-disk electrode was applied. True electrocatalytic activity (kinetic current densities for glucose oxidation) of ε-MnO₂ samples in an isotonic NaCl-based phosphate-buffered saline (pH 7.40) was retrieved and compared. Long-term stability of ε-MnO₂ glucose oxidation currents was further analyzed. For the most active ε-MnO₂ sample a linear square root concentration plot in the broad physiological glucose range (1–60 mM) covering both hypoglycemic and hyperglycemic comatose states was observed. In addition, glucose selectivity of ε-MnO₂ with respect to some common interferent substances (fructose, galactose, xylose, ribose, urea, lactic acid, acetone, ascorbic acid, paracetamol) was verified.</p> Graphical abstract <p></p>