A highly sensitive fluorescent sensor based on small molecules doped in electrospun nanofibers: Detection of explosives as well as color modulation

Fluorescent polymer nanofibers have wide applications in the fields of nano-photonics, nano-optoelectronics, chemical sensors and light-emitting diodes. The doping of small fluorophores into low-cost polymers is a proven alternative route to produce cost-effective and high-performance optical materials. In order to gain deep insight into the photophysical processes of small molecule-doped polymer nanofiber systems and obtain highly sensitive and cost-effective explosive fluorescent sensors, a new type of highly sensitive low-cost sensor for nitro-compounds was synthesized based on PEO/MePyCz (polyethylene oxide/4-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-9-(pyren-1-yl)-9H-carbazole) composite nanofibers. It exhibited fast response and high quenching efficiency towards DNT vapor, which may be attributed to an improved exciton migration of MePyCz in PEO in addition to the large driving force of the electron transfer and the nanofibrous structures. Additionally, it promoted a fluorescence resonance energy transfer process in the polymer fibrous matrix with a green-emitting material of 2-(thiophen-2-yl)-fluoren-9-one. The sensing composite nanofibrous film had good sensitivity and selectivity and might be constructed into a portable detector for explosives.