New lanthanide ternary complex system in electrospun nanofibers: Assembly, physico-chemical property and sensor application

The generation of novel optical sensing structures through the lanthanide coordination has been a key scientific endeavor. The design of molecular indicator for chemical response is derived from the assembly of a polymeric-based ternary europium (III) complex system (Eu(NTA)3L/PVA (NTA = 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dione, L = 2-(4-(4-(allyloxy)phenyl)-6-(pyridin-2-yl)pyridin-2-yl)pyridine, PVA = poly(vinyl acetate)). The electrospinning technique has been employed to create a nanometer scale membrane and this functional film with ultrafine fibers (diameter of about 110 nm) exhibits intense red light at 618 nm under ultra-violet excitation of 340 nm. The luminescent signal transduction involves the interaction of hydrogen chloride (HCl) with the organic ligand. The strong acidity of the analyte induces dissociation of complex network and the evolution of emission from red to blue has been observed. The fabricated nanosensor demonstrates rapid response time (<2 s) and the detection limit has been calculated to be 3.0 ppm. This effective strategy for achieving lanthanide complex-encapsulated polymer fibers will contribute to the development of new intelligent photonic devices.