Photoelectrochemical Nanofiber Ferritin Sensor with Integrated “Migrating‐Destructing‐Detecting” Capability

Abstract Conventional photoelectrochemical (PEC) protein sensors typically rely on steric hindrance to reduce photoelectric signals; however, this photoelectron‐reducing model inherently limits protein accumulation at the sensing interface, thereby reducing detection sensitivity. By contrast, this study introduces an ultrasensitive PEC nanofiber‐based ferritin sensor that employs a signal‐enhanced mechanism by constructing numerous Ag 2 O/Ag heterojunction nanoreactors along the nanofibers. Hydrophilic closed‐loop nanostructures simultaneously integrate the migrating‐destructing‐detecting methods of ferritin within a single nanoreactor, resulting in enhanced photoelectric signals. This PEC nanofiber ferritin sensor exhibits a wide linear range of 10 −8 –10 2 mg mL −1 and superhigh sensitivity of 5 pg mL −1 . Building on this platform, an ion signal‐enhanced response device is developed to facilitate rapid and precise monitoring of proteins across low, normal, and high ferritin levels, enabling precise assessment under various pathological conditions. These findings establish a robust framework for ferritin detection using PEC protein sensing technologies.