Title
A circular dichroism sensor for selective detection of Cd2 + and S2 − based on the in-situ generation of chiral CdS quantum dots
Author
Pradthana Sianglam, Sirinan Kulchat, Thawatchai Tuntulani, Wittaya Ngeontae
Year
2017
Journal
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Abstract
We demonstrate an advance in the fabrication of circular dichroism (CD) sensors for detection of Cd2 + and S2 − based on chiral CdS quantum dots (QDs) generated by a facile in-situ reaction. The chiral quantum dots are generated in solutions composed of Cd2 +, S2 −, cysteamine (CA) and L-penicillamine (L-PA), with the number of the generated particles limited by either the Cd2 + or S2 − concentration. We show that the magnitude of the CD signal produced by the QDs is linearly related to the initial concentration of Cd2 + and S2 −, with excellent selectivity over other ions. Our sensor functions over concentration ranges of 65–200 μM and 7–125 μM with detection limits of 59.7 and 1.6 μM for Cd2 + and S2 −, respectively. The sensor is applied in real water samples with results comparing favorably with those obtained from ICP-OES (for Cd2 +) and HPLC (for S2 −).
Instrument
J-815
Keywords
Circular dichroism, Stereochemistry, Ligand binding, Materials