Related Experiment Video
Updated: Feb 18, 2026

Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes
Published on: January 10, 2017
Chiral recognition of tryptophan enantiomers using chitosan-capped silver nanoparticles: Scanometry and
Marzieh Jafari1, Javad Tashkhourian1, Ghodratollah Absalan1
1Professor Massoumi Laboratory, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454, Iran.
Abstract:
A new, fast and inexpensive colorimetric sensor was developed for chiral recognition of tryptophan enantiomers using chitosan-capped silver nanoparticles. The function of the sensor was based on scanometry and spectrophotometry of the colored product of a reaction solution containing a mixture of chitosan-capped silver nanoparticles, phosphate buffer and tryptophan enantiomers. The image of the colored solution was taken using the scanometer and the corresponding color values were obtained using Photoshop software which subsequently were used for optimization of the experimental parameters as the analytical signal. Two types of color values system were investigated: RGB (red, green and blue values) and CMYK (cyan, magenta, yellow and black values). The color values indicated that L-tryptophan had better interaction than D-tryptophan with chitosan-capped silver nanoparticles. A linear relationship between the analytical signal and the concentration of L-tryptophan was obtained in the concentration range of 1.3 × 10-5-4.6 × 10-4molL-1. Detection limits, were obtained to be 2.1 × 10-6, 2.4 × 10-6 and 3.8 × 10-6molL-1 for L-tryptophan based on R (red), G (green) and B (blue) values, respectively.
Related Concept Videos
Chirality in Nature
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Prochirality
¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
Molecules with Multiple Chiral Centers
Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...

