Carbon dots (CDs) are light-emitting nanoparticles with potential applications in biology and medicine. This study investigated the optical chirality of CDs synthesized from citric acid, ethylenediamine, and various chiral precursors (L-cysteine, L-glutathione, L-phenylglycine, and L-tryptophan). The resulting CDs exhibited high photoluminescence quantum yields (up to 57%), chiral optical signals, and two-photon absorption. Chiral signals originated from a combination of surface-attached precursors, chromophore hybridization within the CDs, and intrinsic core chirality. DFT analysis demonstrated how chiral precursor incorporation induced a strong circular dichroism response. The CDs' optical characteristics remained stable under varying pH and UV exposure, suggesting suitability for bio-applications.

Ananya Das, Evgeny V. Kundelev, Anna A. Vedernikova, Sergei A. Cherevkov, Denis V. Danilov, Aleksandra V. Koroleva, Evgeniy V. Zhizhin, Anton N. Tsypkin, Aleksandr P. Litvin, Alexander V. Baranov, Anatoly V. Fedorov, Elena V. Ushakova