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Updated: Mar 30, 2026

CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
Circular dichroism sensor based on cadmium sulfide quantum dots for chiral identification and detection of
Kessarin Ngamdee1, Theerapong Puangmali2, Thawatchai Tuntulani3
1Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Abstract:
A new chemical sensor based on the measuring of circular dichroism signal (CD) was fabricated from cysteamine capped cadmium sulfide quantum dots (Cys-CdS QDs). The chiral-thiol molecules, d-penicillamine (DPA) and l-penicillamine (LPA), were used to evaluate potentials of this sensor. Basically, DPA and LPA provide very low CD signals. However, the CD signals of DPA and LPA can be enhanced in the presence of Cys-CdS QDs. The CD spectra of DPA and LPA exhibited a mirror image profile. Parameters affecting the determination of DPA and LPA were thoroughly investigated in details. Under the optimized condition, the CD signals of DPA and LPA displayed a linear relationship with the concentrations of both enantiomers, ranging from 1 to 35 μM. Detection limits of this sensor were 0.49 and 0.74 μM for DPA and LPA, respectively. To demonstrate a potential application of this sensor, the proposed sensor was used to determine DPA and LPA in real urine samples. It was confirmed that the proposed detection technique was reliable and could be utilized in a broad range of applications.

