Rational Design of Surface-State Controlled Multicolor Cross-Linked Carbon Dots with Distinct Photoluminescence and Cellular Uptake Properties

Abstract

We disclose for the first time a facile synthetic methodology for the preparation of multicolor carbon dots (CDs) from a single source barring any chromatographic separations. This was achieved via sequential intraparticle cross-linking of surface abundant carboxylic acid groups on the CDs synthesized from a precursor to control their photoluminescence (PL) spectra as well as affect their degree of cellular internalization in cancer cells. The change in PL spectra with sequential cross-linking was projected by theoretical density functional theory (DFT) studies and validated by multiple characterization tools such as X-ray photoelectron spectroscopy (XPS), PL spectroscopy, ninhydrin assay, etc. The variation in cellular internalization of these cross-linked CDs was demonstrated using inhibitor assays, confocal microscopy, and flow cytometry. We supplemented our findings with high-resolution dark-field imaging to visualize and confirm the colocalization of these CDs into distinct intracellular compartments. Finally, to prove the surface-state controlled PL mechanisms of these cross-linked CDs, we fabricated a triple-channel sensor array for the identification of different analytes including metal ions and biologically relevant proteins.

Biomimetic Surface-Enhanced Raman Scattering Nanoparticles with Improved Dispersibility, Signal Brightness, and Tumor Targeting Functions

“…The cytotoxic effects of various AuNPs in two different endothelial cell lines (MDA-MB231, PANC-1) were investigated using MTT assay established previously. − …”

Small Molecule NIR‐II Dyes for Switchable Photoluminescence via Host –Guest Complexation and Supramolecular Assembly with Carbon Dots

“…It was understood that the supramolecular assembly, discussed herein, can be better explained by single crystal structures. Although CB inclusion complexes were studied by single crystal geometries, [ 62 , 63 , 64 ] carbon dots are generally amorphous in nature, [ 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 ] as observed in its powder X‐ray diffraction pattern, and do not crystallize. Hence, the formation of single crystals has not been attempted in this study.…”

The Emerging Development of Multicolor Carbon Dots

“…In 2021, Srivastava et al. [ 105 ] first disclosed a simple synthetic method for preparing multicolor CDs from a single source, excluding any chromatographic separation (Figure 20I). This is achieved by sequential intraparticle cross‐linking of surface rich carboxylic acid groups on CDs synthesized from precursors to control their PL spectra and affect their degree of cell internalization in cancer cells.…”

“…Importantly, the design platform can identify other analytes in combination with specific target recognition elements, so as to promote the application of CDs in the field of food safety and environmental monitoring. In 2021, Srivastava et al [105] first disclosed a simple synthetic method for preparing multicolor CDs from a single source, excluding any chromatographic separation (Figure 20I). This is achieved by sequential intraparticle cross-linking of surface rich carboxylic acid groups on CDs synthesized from precursors to control their PL spectra and affect their degree of cell internalization in cancer cells.…”