Tunable Organelle Imaging by Rational Design of Carbon Dots and Utilization of Uptake Pathways

Abstract

Employing one-step hydrothermal treatment of ophenylenediamine and lysine to exploit their self-and copolymerization, four kinds of CDs (ECDs, NCDs, GCDs, and LCDs) are synthesized, possessing different surface groups (CH 3 , C−O−C, NH 2 , and COOH) and lipophilicity which endow them with various uptake pathways to achieve tunable organelle imaging. Specifically, highly lipophilic ECDs with CH 3 group and NCDs with C−O−C group select passive manner to target to endoplasmic reticulum and nucleus, respectively. Amphiphilic GCDs with CH 3 , C−O−C and NH 2 groups prefer caveolin-mediated endocytosis to locate at Golgi apparatus. Highly hydrophilic LCDs with CH 3 , NH 2 and COOH groups are involved in clathrin-mediated endocytosis to localize in lysosomes. Besides, imaging results of cell division, three-dimensional reconstruction and living zebrafish demonstrate that the obtained CDs are promising potential candidates for specific organelle-targeting imaging.

A universal strategy for green and in situ synthesis of carbon dot-based pickling solution

“…Besides, the C1s spectra (Fig. 2b–e) show three distinct carbon states of CC/C–C at 284.6 eV, C–O at 286.4 eV and CO at 288.0 eV, 44 demonstrating the presence of sp 2 C in all the CDs. The relative contents of C–O and CO in FCDs and SCDs are higher than those in GCDs and SSCDs, implying that there are more oxygen-containing functional groups in GCDs and SSCDs.…”

“…The UV-vis absorption spectra (Fig. 3a) of all the CDs exhibit an obvious absorption peak at 283 nm, ascribed to the π–π* transition of sp 2 C. 44 When dispersed in DI water, the four kinds of CDs appear faint yellow or yellowish-brown color when exposed to sunlight and emit bright green fluorescence when excited by 365 nm UV light, and they show an excitation-dependent PL behavior in aqueous solution (Fig. S4†).…”

One-step synthesized amphiphilic carbon dots for the super-resolution imaging of endoplasmic reticulum in live cells

“…These results suggest that Phe-CDs penetrate into cells and accumulate in ER mainly through a passive diffusion manner, due to their small size and the amphiphilicity property make the more easily interact with the amphiphilic phospholipid bilayer membrane. 33 …”

“…Because the cellular uptake pathway of nanomaterials may play a predominate role in their subcellular localization. 32,33 We have further investigated the Phe-CDs cellular uptake mechanism. The low temperature (4 °C) and different biochemical inhibitors (chloroquine, chlorpromazine, 2-deoxy- d -glucose, NH 4 Cl) were used to estimate the cellular uptake pathway of Phe-CDs.…”

Carbon Dots in Bioimaging, Biosensing and Therapeutics: A Comprehensive Review

“…The carboxyl group content can be determined by Boehm titration by mixing CDs and NaHCO 3 solution, and then the mixed solution is titrated with HCl, with pH as the indicated end point. [ 43 ] In another experiment, Kang et al performed alkali titration according to standard methods to measure the total amount of hydroxyl and carboxylic acid, and then conducted conductometric titration to understand the relative content of hydroxyl and carboxylic acid, and finally calculated their respective contents. [ 44 ]…”