In this1 follow-up to our previous paper on MnO2 as a catalyst for H2O2 decomposition Veronika investigated the effect of doping the MnO2-film with Co2+-ions. The doping, which is done by depositing the manganese oxide electrochemically from a solution also containing a cobalt salt, significantly increases the catalytic performance of the MnO2-coated electrode. XPS in combination with quantum chemical modelling indicated that an increase in hydrolysed forms of manganese (Mn–O–H bonds) is responsible for the increase in catalytic activity.
The Co-doped MnO2 film, deposited on an ITO electrode, was incorporated in a microfluidic electrochemical cell to accurately measure the concentration of H2O2 in sample solutions. The goal is to measure H2O2 in blood, because it serves as a vital signalling molecule within biological systems and has potential as a disease biomarker. As Veronika points out in the introduction:
In Ukraine, since the beginning of the war, such studies are unfortunately in demand, in such topics as the influence of polytrauma on the development of oxidative stress in people exposed to blast injuries.
Most of the work was done during a few months of a summer sabbatical, when Veronika returned to Warsaw. However, additional measurements, in response to reviewer questions, were performed in Dnipro in spring, during some of the worst Russian attacks on the city.
Martin’s role in this work was mainly as advisor for the design of the microfluidic setup and SEM imaging.
- V. Poltavets, M. Krawczyk, G. Maslak, M. Jönsson-Niedziółka
Co2+ ion-doped MnO2 electrode for microfluidic H2O2 biosensors: formation, characterization, and catalytic performance, Dalton Trans. 55, 7577-7587 (2026). (link)
