Abstract
Creating a sensitive and selective method that can provide simple, practical and high-throughput determination of levels of Hg2+ ions in water has proved extremely challenging. This work responds to these challenges by designing, fabricating and evaluating a polyaniline (PANI) based immobilized sensor optimized to exhibit a colorimetric response to trace amount of Hg 2+ ions. The sensor design is realized using a leucoemeraldine based PANI as probe, which has a specific interaction with Hg2+ and results in both "off-on" and "color-change" signals. Hierarchical structured nanofibrous sensing membranes within well immobilized probes are fabricated by a bottom-up blending electrospinning nanofabrication method. This sensor shows a vivid colorimetric response specifically to Hg2+ ions (white-yellow/green-green-blue) over other possible interfering metal cations and achieves a low detection limit of 5 nM observed by the naked eye. Additionally, the sensing responses are visualized quantitatively by employing a colorimetric framework that translates measured spectra into numeric color values directly related to color perception. Furthermore, the as-prepared sensors exhibited good reversibility after extended regeneration cycles, which suggests a promising analytical method as an economical alternative to traditional Hg2+ sensors and also provides a new insight into the design and development of a novel colorimetric sensing system based on PANI immobilized materials.
Original language | English |
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Pages (from-to) | 645-652 |
Number of pages | 8 |
Journal | Journal of Materials Chemistry A |
Volume | 2 |
Issue number | 3 |
DOIs | |
State | Published - 21 Jan 2014 |