Search

The first use of electrospun nanofibrous materials as highly responsive fluorescence quenching-based optical CO sensors is reported. Poly(methyl methacrylate) and ethyl cellulose were used as polymeric materials. Sensing slides were fabricated by electrospinning technique. A fiber-optic bundle was used for the gas detection. CO sensors based on the change in the fluorescence signal intensity of ion pair form of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS). The sensor slides showed high sensitivities due to the high surface area-to-volume ratio of the nanofibrous membrane structures. The preliminary results of Stern-Volmer analysis show that the sensitivities of electrospun nanofibrous membranes to detect CO are 24 to 120 fold higher than those of the thin film based sensors. The response times of the sensing reagents were short and the signal changes were fully reversible. The stability of ion pair form of HPTS in the employed matrix materials was excellent and when stored in the ambient air of the laboratory there was no significant drift in signal intensity after 7 months. Our stability tests are still in progress. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the first use of electrospun nanofibrous materials as highly responsive fluorescence quenching-based optical silver sensors is reported. Poly(methyl methacrylate) and ethyl cellulose were used as polymeric support materials. Silver sensing materials were fabricated by electrospinning technique. A fiber-optic bundle was used for measurements. Sensors were based on the change in the fluorescence signal intensity of methoxy azomethine ionophore (M-AZM). The preliminary results of Stern–Volmer analysis show that the sensitivities of electrospun nanofibrous membranes to detect silver ions are 10–100-fold higher than those of the thin film based sensors. The extraordinary sensitivities can be attributed to the high surface area of the nanofibrous membrane structures. It was found that the stability of the sensing agent in the employed matrix materials was excellent and when stored in the ambient air of the laboratory there was no significant drift in signal intensity after 5 months. Our stability tests are still in progress. [Copyright &y& Elsevier]