Triphenylamine-based dicyano fluorophore for the selective detection of hydrazine vapor using cellulose acetate nanofibrous sheet

Abstract

A novel triphenylamine-based dicyano fluorophore (compound 2) was successfully synthesized using a Suzuki cross-coupling reaction, followed by a Knoevenagel condensation catalyzed with baker's yeast. Later, compound 2 was combined with the hydrazine vapor of an electrospun nanofiber sheet, depending on its solid condition. In addition, the electrospinning technique was used to create a nanofiber sheet made of cellulose acetate (CA) combined with compound 2. The resulting sheet had an average diameter of 250 ± 41 nm. The nanofiber sheet had a remarkable ability to detect and respond to hydrazine vapor in an aqueous solution. The concentration range of 0–0.08% w/v was accurately determined by analyzing fluorescence images using ImageJ software. The mechanism was confirmed by conducting a ¹H-NMR titration. The probe could function effectively across various pH levels from 4 to 11. It also provided an impressive detection limit as low as 0.005% (w/v). In addition, it showed high selectivity for hydrazine among 36 common interferents. Through careful analysis, it was discovered that the nanofibrous mat could detect and identify hydrazine. This was achieved through a visual detection method, whereby the mat exhibited a fluorescence turn-off effect when exposed to UV light with a wavelength of 365 nm. Thus, using a nanofibrous mat is a highly effective and appropriate technique for detecting hydrazine vapor in water in various environments and industries.