One‐Pot Green Synthesis of Nitrogen‐Doped Carbon Quantum Dots for Cell Nucleus Labeling and Copper(II) Detection

Abstract

The doping of nitrogen into carbon quantum dots is vitally important for improved fluorescence performance. However, the synthesis of nitrogen-doped carbon quantum dots (N-CQDs) is usually conducted under strong acid and high temperature, which results in environmental pollution and energy consumption. Herein, the N-CQDs were prepared by a mild one-pot hydrothermal process. The hydrothermal reaction temperature was adjusted to control the particle size, nitrogen/carbon atomic ratio, and quantum yield. The products were water soluble with a narrow particle size distribution and good dispersion stability over a wide pH range. The N-CQDs could penetrate into the HeLa cell nucleus without any further functionalization. Moreover, the fluorescence of N-CQDs could be selectively quenched by Cu , which suggested applications for the detection of Cu in human plasma.

Fluorescent Carbon Dots for Selective Labeling of Subcellular Organelles

“…Targeting the nucleus for drug delivery is essential, especially for cancer therapy, in which the drug interferes with the proliferation of cancer cells. CDs have been found to be an efficient agent for nucleus labeling and a nanocarrier for nucleus-targeted therapy without or with postmodification of nuclear-targeting ligands. ,,,,− For example, N-doped CDs synthesized from ascorbic acid and branched polyethyleneimine with small sizes (∼4 nm) and a zwitterionic surface are efficient for internalization and targeting of the nucleus . Zwitterionic nanoparticles with high colloidal stability over a wide pH range and resistant to nonspecific adsorption of proteins have prolonged blood circulation to enhance their accumulation in tumors.…”

Nitrogen-doped carbon dots as a probe for the detection of Cu2+ and its cellular imaging

“…Recently, nanoparticle-based fluorescence probes have been developed to widely detect Cu 2+ owing to their high sensitivity and simplicity. [30][31][32][33][34][35] For example, Zhao et al 36 synthesized highly luminescent, surface-different, N-CDs using ionic liquids as precursors for the detection of Cu 2+ and cell imaging. Tian et al 37 developed a highly efficient fluorosensor based on ultrathin graphitic carbon nitride (g-C 3 N 4 ) nanosheets for the detection of Cu 2+ .…”

Synthesis of N-doped carbon dots and application in vanillin detection based on collisional quenching

“…This result agrees with that of an earlier report, which may be attributed to the optical selection of the quantum effect with different sized nanoparticles, different emissive traps, and different polyaromatic fluorophores on the structure of the NCD core. 36 Therefore, the fluorescence intensity was recorded with the excitation and emission wavelengths set at 323 and 416 nm, respectively.…”