4,4′-Fluoresceinoxy bisphthalonitrile (FPN)-incorporated polycaprolactone electrospun membranes: a portable sensor strip for detection of Fe3+ ions

4,4′-Fluoresceinoxy bisphthalonitrile (FPN) fluorophore-incorporated electrospun nanofibrous sensor strips have been fabricated for selective detection of Fe3+ ions in aqueous solutions. Polycaprolactone (PCL) was used as the primary polymer matrix. PCL/FPN nanofibrous membranes were prepared by solution electrospinning technique. Fibrous morphology was evaluated using scanning electron microscopy (SEM). The fabricated membranes were characterized using IR spectroscopy, contact angle measurements and mechanical strength evaluation. The characteristic emission properties of PCL/FPN membranes were monitored by fluorescence spectroscopy. Selective detection of Fe3+ ions using PCL/FPN fibrous strips was confirmed by analyzing its ability in different metal ion solutions. The limit of detection for Fe3+ ions was examined at a concentration range of 10–70 nM and was found to be 2.9413 nM. The lower limit of detection observed for PCL/FPN membranes proves its high selectivity and sensitivity toward Fe3+ ions.