Fluorescent nanofibrous membrane (FNFM) for the detection of mercuric ion (II) with high sensitivity and selectivity

A highly sensitive and selective fluorescent nanofibrous membrane (FNFM) for the detection of mercuric ions (II) was prepared via electrospinning and subsequent immobilization. In this process, fluorescent chemosensor dithioacetal-modified perylenediimide (DTPDI) was introduced on the surface of polyacrylonitrile (PAN) nanofibers with high stability under mechanical force by electrostatic interaction. Because DTPDI can be detached from PAN nanofibers due to the hydrolysis of dithioacetals in the presence of Hg2+ and form an oil-soluble fluorescence dye AL. According to the linear correlation between AL and Hg2+, the obtained FNFM could be employed for the detection of Hg2+. Results reveal that the FNFM exhibits high sensitivity for the detection of Hg2+ and no interference from other metal ions. The limit of detection for Hg2+ can reach as low as 1 ppb. In addition, the strong fluorescence of FNFM still can be observed even after the repeated use for 7 times. Therefore, FNFM can be developed as a rapid, portable and stable sensor for the detection of Hg2+. Moreover, FNFM can execute other functions by changing the probe immobilized on the surface of nanofiber. (C) 2016 Elsevier B.V. All rights reserved.