Electrospun nanofiber based colorimetric probe for rapid detection of Fe~(2+) in water

摘要

An imidazole derivative, 2-(2'-pyridyl)imidazole (PIMH), was developed as a colorimetric probe for the qualitative analysis of Fe~(2+) in aqueous solution. PIMH was then used to post-functionalize poly(vinylbenzyl chloride) (PVBC) nanofibers after electrospinning so as to afford a solid state colorimetric probe. Upon treatment with Fe~(2+) the probe displayed a distinctive color change both in liquid and solid platforms. The linear dynamic range for the colorimetric determination of Fe~(2+) was 0.0988-3.5 μg mL~(-1). The ligand showed a high chromogenic selectivity for Fe~(2+) over other cations with a detection limit of 0.102 μg mL~(-1) in solution (lower than the WHO drinking water guideline limit of 2 mg L~(-1)), and 2 μg mL~(-1) in the solid state. The concentration of Fe~(2+) in a certified reference material (Iron, Ferrous, 1072) was found to be 2.39 ± 0.01 mg L~(-1), which was comparable with the certified value of 2.44 ± 0.12 mg L~(-1). Application of the probe to real samples spiked with Fe~(2+) achieved recoveries of over 97% confirming accuracy of the method and its potential for on-site monitoring.