Organic semiconductors-coated polyacrylonitrile (PAN) electrospun nanofibrous mats for highly sensitive chemosensors via evanescent-wave guiding effect

We report the first use of organic semiconductors (OSCs)-coated PAN nanofibrous mats as highly responsive fluorescence quenching-based chemosensors for 2,4,6-trinitrotoluene (TNT) and H2O2 detection in vapor phase. We report the first use of organic semiconductors (OSCs)-coated PAN nanofibrous mats as highly responsive fluorescence quenching-based chemosensors for 2,4,6-trinitrotoluene (TNT) and H2O2 detection in vapor phase. Conjugated polymers, poly(triphenylaminealt-biphenylene vinylene) (TPA-PBPV), and small organic molecules, 1-boronic-ester pyrene and 1,6-bisboron-ester pyrene, were coated onto the nanofibers fabricated by electrospinning. By introducing the nanofibers structure, a 9-fold fluorescence intensity enhancement and a 14-fold sensitivity enhancement were achieved, which could be attributed to its high area-to-volume ratio, excellent gas permeability, and more importantly, the evanescent-wave effect occurred once the diameters of the fibers were small enough. Since the organic semiconductors coated onto the nanofibrous mats could be replaced by other functional materials, the nanofibers-enhanced detection strategies could be extended to more general domains including chemical and environmental detection.