One-step assembly of fluorescence-based cyanide sensors from inexpensive, off-the-shelf materials

Abstract

We report a simple and versatile approach to assemble sensitive and selective fluorescence “turn-on” sensors for cyanide by combining three off-the-shelf materials; namely fluorescent dye, 1-vinyl imidazole polymer, and cupric chloride. The cyanide-sensing species is a non-fluorescent fluorophore-polymer-Cu2+ complex; which forms as a result of the imidazole polymer’s ability to bind both fluorophore and fluorescence quencher (Cu2+). Cyanide removes Cu2+ from these complexes; thereby “turning-on” sensor fluorescence. These sensors are water-soluble and have a detection limit of ~2.5 μM (CN-) in water. Our ternary complex-based sensing approach also enables facile emission tuning; we demonstrate the convenient, synthesis-free preparation of blue and green-emitting sensors using distyrylbiphenyl and fluorescein fluorophores, respectively. Furthermore; these ternary complexes are easily immobilized using agarose to create cyanide-sensing hydrogels; which are then used in a simple; novel microdiffusion apparatus to achieve interference-free cyanide analysis of aqueous media. The present study provides an inexpensive approach for portable; interference-free cyanide detection.

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© 2020 by the authors. Licensee MDPI, Basel, Switzerland. cc-by

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Keywords

Agarose, Complex, Cyanide, Fluorescence, Hydrogel, Microdiffusion, Non-covalent, Off-on, Sensor, Turn-on

Citation

Fernandes, G.E., Chang, Y.-W., Sharma, A., & Tutt, S.. 2020. One-step assembly of fluorescence-based cyanide sensors from inexpensive, off-the-shelf materials. Sensors (Switzerland), 20(16). https://doi.org/10.3390/s20164488

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