Polyol-Mediated Synthesis of Nitrogen-Containing Carbon-Dots from Tetracyanobenzene with Intense Red Fluorescence

Abstract

Nitrogen-containing C-dots were prepared by heating (160 °C, 1 h) 1,2,4,5-tetracyanobenzene (TCB) in polyethylene glycol 400 (PEG400). The as-prepared monocrystalline C-dots were 2–4 nm in diameter and contained 24.4 wt. % of nitrogen. They showed intense fluorescence under excitation at 400–500 nm as well as under excitation at 600–700 nm. In addition to an excitation-wavelength-depending emission at 400 to 650 nm, the emission spectra exhibited a strong emission peaking at 715 nm, whose position was independent from the wavelength of excitation. For this deep-red emission a remarkable quantum yield of 69% was detected. The synthesis of nitrogen-containing C-dotswas completely performed in the liquid phase. Moreover, the C-dots could be directly dispersed in water. The resulting aqueous suspensions of PEG400-stabilized nitrogen-containing C-dots also showed intense red emission that was visible to the naked eye.

A novel method for synthesis of carbon dots and their applications in reactive oxygen species (ROS) and glucose detections

“…Furthermore, Bragg peaks associated with L-lactose, which was used as the starting material, are absent. [21][22][23]…”

Polyol Synthesis: A Versatile Wet-Chemistry Route for the Design and Production of Functional Inorganic Nanoparticles

“…Selected recent results dealing with all these aspects, at least some of them, are highlighted in this series. Typically, Lehmacher et al [ 54 ] present a polyol-mediated synthesis of nitrogen-containing C-dots with 1,2,4,5-tetracyanobenzene as a starting material. This one-pot liquid-phase synthesis provides, with a good reliability, particles with interesting features—such as a narrow size distribution (2–4 nm), high crystallinity, high dispersibility in water, and deep-red fluorescence—which may be used as emitting biomarkers for histology.…”