Synthesis of Highly Fluorescent Yellow‐Green N‐Doped Carbon Nanorings for pH Variation Detection and Bioimaging

Abstract

A facile and direct chemical route is developed to produce intercrossed N‐doped graphene carbon nanorings (N‐CNRs) with a high yellow‐green photoluminescence emission in both solid and aqueous states. The N‐CNRs are directly synthesized at an elevated temperature in an inert atmosphere without additional pressure using urea and sodium citrate as raw materials. N‐CNRs have a photoluminescence change phenomenon from green to blue when the pH is altered from a neutral to a base value. The luminescence mechanism is analyzed under absorbance and lifetime decay, X‐ray photoelectron spectra, and X‐ray absorption near edge structure spectroscopy. Results indicate how the optical properties are tuned. The fluorescence bioimaging of zebrafish using N‐CNRs as the probe is also studied in terms of zebrafish husbandry, embryo harvesting, and the introduction of N‐CNRs into embryos and juveniles by soaking and microinjection. The prepared N‐CNRs serve as a promising fluorescent probe for pH variation analysis, and bioimaging. The N‐CNTs show potential for use in air purification applications.

Commercial Wheat and Oat Flour Derived Fluorescent Carbon Quantum Dots through Sustainable Hydrothermal Synthesis and Their Biological Activities

“…The nitrogen and phosphorus co‐doped CQDs (NP‐CQDs) showed a broad and wide centered diffraction peak at 2θ=23° and a weak peak at 2θ=42° that are attributed to the (002) and (001) lattice spacing of amorphous graphitic CQDs, respectively. Xu et al [41] . (2008) also reported the XRD pattern of CDs that showed a broad and hump centered diffraction peak at 2θ=26.7°, assigned to the (002) diffraction pattern of graphitic carbon.…”

Interconnected 3D carbon network with enhanced reaction kinetics and architecture stability for advanced potassium-ion hybrid capacitors

“…Generally, sodium citrate and urea were used as raw materials to construct N-doped carbon. [21][22][23] Thus, the overall preparation and construction procedures of NPC are depicted in Fig. 1a.…”

“…24 The bubbles gradually converted into a threedimensional interconnected carbon network composed of a carbon nanosheet through the synergistic effect of gases and surface tension of molten carbon. 23 Meanwhile, these continuously released gases would cause the generation of some micropores when they passed the bubbles walls. 25 As a template, Na 2 CO 3 could be easily removed via washing the product with water instead of harmful or corrosive reagents (e.g., HCl, HF, or NaOH), thus endowing a synthesis route that was green and eco-friendly.…”

Natural deep eutectic solvent assisted synthesis and applications of chiral carbon dots

“…1C) shows a broad diffraction peak centered at 2θ = 26.42°, which corresponds to the (002) facet of graphite, indicating that CCDs contain graphite-like structures. 25 Raman spectral analysis was further used to study the carbonaceous nanostructure of CCDs. The appearance of two bands at 1331 cm −1 (D band, sp 3 -hybridized) and 1541 cm −1 (G band, sp 2 -hybridized) also indicates that CCDs have a structure similar to nanocrystalline graphene/graphene oxide (Fig.…”