A highly selective and reversible turn-off fluorescent chemosensor for Cu2+ based on electrospun nanofibrous membrane modified with pyrenecarboxaldehyde.

Affiliation

College of Material Science and Engineering, North China University of Science and Technology, Key Laboratory of Functional Polymer Materials of Tangshan, Tangshan 063210, China. Electronic address: [Email]

Abstract

A fluorescent nanofibrous membrane (NFM) was successfully fabricated by functionalizing electrospun ethylene-vinyl alcohol copolymer (EVOH) NFM with 4‑aminobenzoic acid (PABA) and 1‑pyrenecarboxaldehyde (Py-CHO) for fast and selective determination of Cu2+ in aqueous solution. The effective grafting of PABA and Py-CHO on the surface of EVOH NFM was confirmed by FTIR and XPS spectra. Benefiting from the integrated merits of electrospun EVOH NFM, PABA and Py-CHO, the as-appeared EVOH-PABA-Py NFM exhibited high sensitivity and selectivity towards Cu2+ detection. The quenching efficiency was 91.7% when the concentration of Cu2+ reached 5 × 10-3 M, while the detectable fluorescence response of the NFM was still observed when the concentration of Cu2+ was 1 × 10-9 M. The fluorescence quenching caused by Cu2+ was hardly affected by other commonly co-existent metal ions. More importantly, the fluorescent NFM exhibited fast response and high reversibility towards Cu2+ detection. The "off-on" fluorescence switching process via alternating addition of Cu2+ and Na2EDTA occurred in 3 min, and the quenching efficiency of the NFM kept relatively stable values within 10 cycles. This work may provide a new insight into the development of rapid, portable, stable and reusable fluorescent sensor based on electrospun nanofibers that can satisfy the requirements of practical metal ions detection.

Keywords

1‑Pyrenecarboxaldehyde,Cu(2+) sensing,Electrospun nanofibers,Fluorescent sensor,Reversibility,