where 𝑛 is the amount of substance (number of moles) liberated, 𝑄 is the total charge, 𝐹 is the Faraday's constant, and 𝑣 is the valency of the ions. Utilizing this equation, it was determined that nearly 3 × 10 10 molecular oxygen could be produced near the sensing electrodes by applying a positive potential at the protonator electrodes. The comprehensive calculation is provided in the Supplementary data. Consequently, sufficient oxygen would be present to regenerate the oxidized glucose oxidase eliminating oxygen diffusion limitation associated with the Clark type cell . For in-situ electrochemical pH control, identical conditions and solutions were utilized, except that the pH of glucose solutions was not chemically adjusted beforehand and remained at pH 7.4 & pH 6.8 in each case. Instead, a constant oxidizing potential was applied to the protonator IDEs, generating protons (H + ions) and molecular oxygen (O2) according to Eq. 8, thus tailoring the pH in the vicinity of the sensor IDEs. The protonator IDEs were biased by 1.13 V to adjust the pH from 7.4 to pH 5.5 and 1.03 V for adjusting the pH from 6.8 to pH 5.5, using the on-chip RE. The pH control method