Freestanding and binder free PVdF-HFP/Ni-Co nanofiber membrane as a versatile platform for the electrocatalytic oxidation and non-enzymatic detection of urea

Abstract

The freestanding and binder free electrospun polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) composite nanofiber membranes were prepared via in-situ chemical reduction technique and exploited as the efficient electrochemical probes for the electrochemical oxidation and enzyme free detection of urea. The as-prepared membranes exhibited the highly interconnected, homogeneously distributed and smooth surfaced PVdF-HFP nanofibers, in which the face centered cubic nickel (Ni)/Ni-cobalt (Ni-Co) nanoparticles were uniformly anchored. The Ni:Co(0.5:0.5) content in PVdF-HFP nanofibers exhibited the excellent electrochemical properties toward urea electrooxidation as substantiated from the higher anodic current and lower onset potential in comparison with the other compositions of Ni and Co prepared under the similar conditions. Under the optimized conditions, PVdF-HFP/Ni-Co(0.5:0.5) membrane showed the superior electrochemical performances toward non-enzymatic urea detection, offering the rapid response time, lower detection limit, high sensitivity and wide linear range of 5s, 12μM, 2.4μAmM−1cm−2 and 20μM − 2mM, respectively. Owing to the robust frameworks, excellent electrical conductivity, large surface area and extended active sites of PVdF-HFP/Ni-Co(0.5:0.5) membrane, the constructed urea sensor exhibited an excellent stability and favorable reproducibility toward urea oxidation and also endowed its applications in human urine samples with the analytical reliability. These findings embrace the unique strategy for the fabrication of freestanding and binder free electrodes and construct the new possibilities toward the utilization of electrospun polymeric electrodes in urea electooxidation and its precise detection.