Crosslinked PVA electrospinning nanofibrous film as a new platform for the design of K+ sensor

There is an increasing demand for sensitive, selective, and convenient detection tools for disease-related biomarker, potassium ion (K+). Electrospinning nanofibrous film as a novel sensing platform exhibits unique advantages due to high surface area ratio and network structure. In this study, electrospinning technique was employed to construct poly(vinyl alcohol) (PVA) nanofibrous film to assist K+ sensing. To find the best recipe, these factors including probe concentration, solvent composition, spinning time and cross-linking time were explored, and 8 groups of sensing films (F0-F7) were obtained in which F2 was considered the best and used for subsequent tests. Under optimized conditions, the sensing platform F2 was constructed by relatively continuous, uniform fibers with diameters in the range of 150–250 nm, and showed excellent selectivity, reusability, considerable response speed, and high sensitivity in which the fluorescence enhanced factor was as high as 8.9 with 10 mM K+. Moreover, F2 showed high accuracy in real samples detection, and it was used as a real-time K+ sensing platform. The excellent performance of F2 not only proved the reasonable design principle using PVA fibers for K+ sensing, but also could be extended to other probes and lead to different selectivity which was significant for biological diagnosis.