Highly Fluorescent Chiral N‐S‐Doped Carbon Dots from Cysteine: Affecting Cellular Energy Metabolism

Abstract

Cysteine-based chiral optically active carbon dots (CDs) and their effects on cellular energy metabolism, whichis vital for essential cellular functions,have been barely reported. Ag reen and effective synthesis strategy for chiral N-S-doped CDs (fluorescence quantum yield ca. 41.26 %) based on hydrothermal treatment of l-o rd-cysteine at as low as 60 8 8C has been developed. This suggested that cysteine was instable in aqueous solutions and acts as awarning for high-temperature synthesis of nanomaterials using cysteine as stabilizer.Human bladder cancer T24 cells treated with l-CDs showed upregulated glycolysis,w hile d-CDs had no similar effects.I n contrast, no disturbance to the basal mitochondrial aerobic respiration of T24 cells was caused by either chiral CD.Carbon nanomaterials have provoked great interest in various research fields owing to their remarkable properties and potential applications in ab road range of fields. [1] Fluorescent carbon quantum dots (CDs) share the distinguishing electronic and optical characteristics of semiconductor quantum dots while significantly avoiding limitations such as intrinsic toxicity due to the use of heavy metals in their production and/or elemental scarcity. [2] Great attention has been paid to studies on the synthetic approaches of carbon dots. [3] However,c omplex procedures for the subsequent separation and purification have been obstacles to their further development. Thecomplexity also makes the production of CDs on al arge scale difficult. Furthermore,s ome issues such as their poor solubility in water, low fluorescence quantum yields,a nd difficult functionalization need to be addressed before they can truly outperform semiconductor quantum dots in areas such as bioimaging and nanomedicine. [1a,d, 4] When considering the potential biological applications of CDs,c hirality is an important factor that significantly influences material performance but has not been carefully addressed so far. [5] Natural processes include many phenomena in which the chirality of biomolecules plays an important role in the fields of biology and medicine.Adeep understanding of the fundamental concepts relevant to chirality in nanostructures is important for the further development of nanomaterials. [5,6] Some seminal work on chiral semiconductor quantum dots and noble metal nanostructures and their chirality-dependent properties has been reported. [6,7] However,chiral nanobio-interactions have barely been reported in the case of CDs,although they have exhibited great potential for biomedical applications. [8] Herein, agreen and effective synthesis strategy for chiral CDs was developed, and their effects on cellular energy metabolism were studied. Chiral l-CDs and d-CDs were obtained by hydrothermal treatment of l-o rd-cysteine at 60 8 8C, respectively.T his finding demonstrated the stability of cysteine was poor in aqueous solution. There are many amine and carboxyl groups for further functionalization on the surface of the CDs.T he photoluminescence quantum yield is as high a...

Time‐Dependent Phosphorescence Colors from Carbon Dots for Advanced Dynamic Information Encryption

“…As shown in Figures S2 and S3 in the Supporting Information, the carbonyl group signals (165–185 ppm) of the CDs are more intense than those of the r‐CDs, which indicate the reduction of CO groups in the r‐CDs. [ 17 ]…”

Carbon Dots: A New Type of Carbon-Based Nanomaterial with Wide Applications

“…The facile approach, high QY, low toxicity, and high resistance to photobleaching of CDs caused widespread concern and a research boom. Thereafter, researchers developed different strategies and technologies to pursue CDs with high performance, and lots of significant breakthroughs have taken place in the past few years, including multicolor/deep red/near-infrared (NIR) emission, 2 , 13 − 18 narrow full width at half maximum (FWHM), 2 , 9 , 19 , 20 two-/multiphoton PL, 2 , 15 , 16 , 21 chirality, 22 , 23 room temperature phosphorescence (RTP), 3 , 24 − 27 and thermally activated delayed fluorescence (TADF) 28 as well as various applications.…”

Selenium-Sulfur-Doped Carbon Dots with Thioredoxin Reductase Activity

“…request of the author prior to copyediting and composition. We further employed Ultraviolet and visible spectroscopy (UV-vis) and Fourier Transform Infrared Spectroscopy (FT-IR) to differentiate Se-S-CDs apart from the single element doped CDs, i.e., Se-CDs and S-CDs 52 . From the UV-vis spectra (Figure S4a), we can recognize the obvious changes in absorbance peak position between the three CDs.…”

“…The Se-S-CDs exhibited uniform size distribution of 5-8 nm and improved quantum yield of 13.27%. Different from the Sedoped CDs 49 , S-doped CDs 52 , or any other dichalcogenide quantum dots 25 , the Se-S-CDs could significantly promote cell viability via enhancing the TrxR activity, which is attributed to the doping of Se-S bonds and the carbon dots as matrix. Additionally, the Se-S-CDs could also revive the cells…”