Binder-less and free-standing Co–Fe metal nanoparticles-decorated PVdF-HFP nanofiber membrane as an electrochemical probe for enzyme-less glucose sensors

Co–Fe bimetallic nanoparticles-affixed polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) nanofiber membrane is fabricated using the electrospinning and chemical reduction techniques. The semicrystalline polymeric backbone decorated with the highly crystalline Co–Fe bimetallic nanoparticles enunciates the mechanical integrity, while the incessant and swift electron mobility is articulated with the consistent dissemination of bimetallic nanoparticles on the intersected and multi-layered polymeric nanofibers. The diffusion and adsorption of glucose are expedited in the extended cavities and porosities of as-formulated polymeric nanofibers, maximizing the glucose utilization efficacy, while the uniformly implanted Co⁴⁺/Fe³⁺ active centers on PVdF-HFP nanofibers maximize the electrocatalytic activity toward glucose oxidation under alkaline regimes. Thus, the combinative sorts including nanofiber and nanocomposite strategies of PVdF-HFP/Co–Fe membrane assimilate the enzyme-less electrochemical glucose detection concerts of high sensitivity (375.01 μA mM^?1 cm^?2), low limit of detection (0.65 μm), and wide linear range (0.001 to 8 mM), outfitting the erstwhile enzyme-less glucose detection reports. Additionally, the endowments of high selectivity and real sample glucose-sensing analyses of PVdF-HFP/Co–Fe along with the binder-less and free-standing characteristics construct the state-of-the-art paradigm for the evolution of affordable enzyme-less electrochemical glucose sensors.

     

Colorimetric Sensing of Toxic Metal and Antibacterial Studies by Using Bioextract Synthesized Silver Nanoparticles

Here, we report the simple and cost effective colorimetric technique for the determination of toxic metals (Hg²⁺) in aqueous sample by using bioextract silver nanoparticles (AgNPs). The indigenous AgNPs were synthesised by green and ecologically friendly style using extract of fig (Ficus carica) leaf. The synthesized AgNPs were confirmed by UV–vis spectroscopy, FT-IR spectroscopy, and scanning electron microscopy methods. The synthesis of AgNPs was observed by its colour changing from light yellow to dark brownish. The existence of furanocoumarins bioactive materials in the fig leaf extract, which act as bio-reducing and capping agent, help in the formation of stabilized silver nanoparticles. In addition, the bacterial activity of the synthesized silver nanoparticles was tested against gram-negative (Klebsiella oxytocam, Pseudomonas aeruginosam, Shigella flexneri and Proteus mirabilis), gram-positive (Staphylococcus aureus and Micrococcus luteus) and one Candida (Candida albicans) human pathogen and the results showed moderate activity.