Browsing by Author "Laschuk, N. O."

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Multi-readout logic gate for selective metal ions detection in parts per billion levels
(John Wiley & Sons, Ltd., 2016-07-18) Zenkina, O. V.; Laschuk, N. O.; Ebralidze, I. I.; Spasyuk, D.
Optical sensors utilizing visual responses for the identification of metal ions require reliable molecular systems able to operate selectively in multicomponent solutions. Herein, we report a water-soluble terpyridyl-based ligand that demonstrates effective quantification of parts per billion to parts per million levels of Fe2+, Fe3+, Zn2+, and Ru3+. Whereas the Fe3+ and Ru3+ ions were found to bind to the ligand to form a monometallic complex, a 2:1 ligand/metal binding stoichiometry was found for the Zn2+ and Fe2+ complexes. The corresponding metal-binding events were directly translated into distinct colorimetric and spectroscopic logic outputs. Applying molecular logic (Boolean logic operations) to describe these binding events, selective discrimination between the ions was demonstrated
Rational design of a material for rapid colorimetric Fe2+ detection
(Elsevier, 2016-10-05) Zenkina, O.V; Laschuk, N. O.; Ebralidze, I. I.; Quaranta, S.; Kerr, S.; Egan, J. G.; Gillis, S.; Gaspari, F.; Latini, A.
We report on the rational design of a novel TiO2 based screen-printed material suitable for sensitive and selective detection of iron ions in water. This includes the synthesis and characterization of large mesoporous TiO2 nanostructures, screen-printing of thick titania films on glass surfaces and their functionalization with 2,2′:6′,2″-terpyridin-4′-ylphosphonic acid (terpy). The ultra-high affinity between iron ions and the TiO2-anchored terpy receptor makes this system potentially applicable to the analysis of iron in environmental, food, biological, and biomedical systems by a readily quantifiable colour change. Rapid (< 30 s) colour change of the material from white to magenta permits easy detection of as low as 0.3 ppm of Fe2 + by the naked eye. The intensity of the colour change depends on the nature of the nanoparticles, the overall TiO2 film thickness, and the Fe2 + concentration. The material was characterized using profilometry, diffuse reflectance UV–vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) before and after treatment with aqueous solutions of Fe2 +. The designed material shows colour reversibility upon treatment with EDTA solutions, which allows for multiple reuses of the same film with no effect on sensitivity.