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Bioresorbable electrochemical sensors remain mostly unexplored despite their ability to provide continuous in situ measurements of critical biomarkers. The primary challenge arises from the direct exposure of the electrodes' thin metal films to biofluids, which poses difficulties in ensuring both proper operational lifetimes and sensing performance. Molybdenum (Mo) presents itself as a promising biometal due to its uniquely gradual dissolution in biofluids, facilitated by the formation of a slower‐dissolving MoOx surface layer. Consequently, carefully engineered MoOx films can endow transient electrochemical sensors with unparalleled stability during extended operational lifetimes. Herein an unprecedented sensor architecture achieved via the unique pairing of sputtered Mo and MoOx thin films, probed as a pH and dissolved oxygen sensor is reported. Compared to a bare Mo electrode, a bilayer Mo+MoOx electrode subjected to post‐deposition annealing (400 °C, 60 min, N2 environment) displayed a largely improved stability (>24 h) in solution and demonstrated predictable functionality during ongoing film dissolution at 37 °C. Collectively, this work establishes a pioneering strategy for the fabrication of reliable and clinically relevant implantable electrochemical sensors. [ABSTRACT FROM AUTHOR]

In the search for non‐enzymatic alternatives to glucose oxidase, reliable and microchip‐compatible approaches to catalyst development are highly desirable. Herein, the electrochemical behavior of thin films of VOx deposited by molecular beam epitaxy (MBE) on glassy carbon electrodes is reported. A process of partial etching during polarization is observed. Thereafter, highly active and stable traces of VOx act as catalytic centers for glucose electrooxidation. A mechanistic description of the electrochemical process is proposed based on evidence provided by voltammetric measurements. The sensors are calibrated both with potentiometric and amperometric techniques, the former showing a wide linear range (1–10 mM), good sensitivity (14.93 ± 0.39 µA cm−2 × mM–1) and a limit of detection (0.32 m‐M). Unlike most metal oxides, it is shown that VOx on glassy carbon is capable of successfully oxidizing glucose at −0.4 V. Such a one‐of‐kind behavior can have important ramifications for energy‐efficient integrated electrochemical sensors and non‐enzymatic glucose sensing as a whole. [ABSTRACT FROM AUTHOR]