Title
Highly selective circular dichroism sensor based on D-penicillamine/ cysteamine cadmium sulfide quantum dots for copper (II) ion detection
Author
Kessarin Ngamdee, Kanokwan Chaiendoo, Chatree Saiyasombat, Wutthikrai Busayaporn, Somlak Ittisanronnachai, Vinich Promarak, Wittaya Ngeontae
Year
2019
Journal
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Abstract
A highly selective circular dichroism sensor based on cysteamine-capped cadmium sulfide quantum dots (Cys-CdS QDs) was successfully developed for the determination of Cu2+. Basically, the Cys-CdS QDs are not active in circular dichroism spectroscopy. However, the circular dichroism probe (DPA@Cys-CdS QDs) can be simply generated in situ by mixing achiral Cys-CdS QDs with D-penicillamine. The detection principle was based on measuring the circular dichroism signal change upon the addition of Cu2+. The strong CD signal of the DPA@Cys-CdS QDs dramatically decreased in the presence of Cu2+, while other cations did not result in any spectral changes. In addition, the degree of the CD signal decrease was linearly proportional to the concentration of Cu2+ in the range of 0.50–2.25 μM (r2 = 0.9919) with a detection limit of 0.34 μM. Furthermore, the proposed sensor was applied to detect Cu2+ in drinking water samples with %recovery values of 102–114% and %RSD less than 6%.
Instrument
J-815
Keywords
Circular dichroism, Cotton effect, Ligand binding, Sensors, Nanostructures, Materials