Chiral Nitrogen-Doped Graphene Quantum Dot Electrochemical Sensor for Recognition of Tartaric Acid Isomers

Abstract

Chirality is a basic attribute of object in three-dimensional space, and the phenomenon of chirality exists widely in nature. By covalently grafting L/D-cysteine to nitrogen-doped graphene quantum dots (NGQDs) through amide reaction, a new type of chiral NGQDs was obtained. Its morphology was characterized by transmission electron microscope, and its structure and composition were determined by X-ray powder diffraction, infrared spectroscopy, raman spectroscopy, ultraviolet spectroscopy and X-ray photoelectron spectroscopy. In the linear cyclic voltammetry test, it is found that chiral NGQDs have different peak current values in different configurations of tartaric acid, and the changes in the peak current intensity can specifically identify L/D-tartaric acid isomers. There are two identical asymmetric carbon atoms in the tartaric acid molecule, which is a by-product of the wine industry. Due to its low price, it is often used to resolve other racemates, such as epinephrine and chloramphenicol. Through the method of molecular simulation and docking calculation, the combination of chiral graphene quantum dots and tartaric acid was studied, and the mechanism of chiral recognition was discussed. This work broadens the application range of graphene quantum dots and provides new ideas for the preparation of chiral inorganic nanomaterials.

Nanoassembly of l-Threonine on Helical Carbon Tubes for Electrochemical Chiral Detection of l-Cysteine

“…33 Therefore, its chiral recognition performance can be attributed to the inherent chiral helical structure. 34,35 Interaction between the chiral selector and enantiomer is a key factor of chiral recognition, 36 so the binding model of L-Thr with L-Cys and D-Cys is built by AutoDock software (Figure 5e). It can be seen that the carboxyl O atom in the structure of L-Thr forms two H-bonds with a sulfhydryl H atom and an amino H atom of L-Cys, and the distance of each H-bond is 2.1 Å.…”

One-Step Solvothermal Synthesis of Red Chiral Carbon Dots for Multioptical Detection of Water in Organic Solvents

“…Low preparation cost, wide varieties of precursors, simple synthesis, low cytotoxicity, and appropriate biocompatibility are other attractive features of the CDs. , In addition, as a newly emerging optical property, chirality is added to the advantages of some recently prepared CDs . Up to now, chiral CDs have been applied for the detection of various materials as a precise fluorescence sensing technique, − and according to our studies, there is no report on the use of UV–visible absorption and especially the chirality of these nanoparticles in the detection of materials.…”