Multimaterial Fibers Interfaced with ZnO for Photoelectrochemical Detection.

The development of miniaturized, remotely addressable sensing devices is crucial in a variety of fields, including healthcare, environmental monitoring, and security. This study introduces an optrode sensor comprising a multimaterial fiber composed of a phosphate glass cladding and a continuous Zn wire core, interfaced with a photoactive ZnO coating on its tip, deposited by anodization. It is shown that this optrode can promote photoelectrochemical reactions under illumination with UV light when immersed in an aqueous electrolyte. Proof-of-principle experiments demonstrate that these optrodes produce a glucose-responsive photocurrent, opening the way to biomedical applications. This optical sensor shows promise, as it would ultimately allow the decoupling of input stimuli, i.e., potential and light excitation, over a long distance. Due to its advantages in terms of integration, detection speed, and ease of use, these ZnO/Zn/phosphate optrodes hold significant potential for remote analysis and implantable sensors.