Blue luminescent amorphous carbon nanoparticles synthesized by microplasma processing of folic acid

Abstract

Environmentally friendly synthesis of carbon nanoprticles (C‐NPs) from folic acid (FA) is realized with the assistance of microplasma. TEM shows that the synthesized FA C‐NPs are amorphous and of diameter around 47 nm. The produced FA C‐NPs exhibit an excitation independent emission around 445 nm with the fluorescence quantum yield 13% at excitation wavelength of 370 nm. X‐ray photoelectron spectroscopy (XPS) shows the FA C‐NPs are composed of carbon (64.15%), nitrogen (6.04%), and oxygen (29.81%). Raman spectroscopy shows that the intensity ratio between the sp3 and sp2 hybridizations of Carbon is 0.35. UV‐Vis absorption, Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR) spectra provide a deep insight into the fluorescence of FA C‐NPs. With plasma processing of FA, carbon atoms are involved in sp2 hybridization and amine (NH2), NH and COOH groups are converted into ROOCNHCOOR group. As a consequence, the electron donating ability of aromatic ring is enhanced, which plays an important role in the fluorescence of FA C‐NPs. Finally, the promising application of FA C‐NPs in bioimaging is also demonstrated by fluorescence labeling of MCF‐7 cancer cells.

Plasma-enabled catalyst-free conversion of ethanol to hydrogen gas and carbon dots near room temperature

“…Based on the above observations and previous studies of formation of carbogenic materials from small molecules, a plausible reaction mechanism of CDs formation is proposed, as shown in Fig. 9 [37][38][39][40][41]. In the first stage, dehydrogenation (oxidation) of ethanol takes place in the presence of plasma-induced highly energetic electrons, yielding diverse radicals such as unsaturated alkenes (-CH=CH-), and alkynes (-C≡C-).…”

Synthesis of Yellow-Fluorescent Carbon Nano-dots by Microplasma for Imaging and Photocatalytic Inactivation of Cancer Cells

“…Therefore, novel environment-friendly synthetic methods emerge as the times require. As it has been reported, CQDs can be produced within just a few minutes using a microplasma-liquid method without high temperature condition, large energy input, and laborious procedures [18][19][20]. Microplasmas supply a unique physicochemical environment to both fundamental studies and applications involving advanced materials.…”

Synthesis of N-doped carbon dots via a microplasma process

“…Thus, element doping study of carbon dots is essential to obtain carbon dots with favourable fluorescent performance. There are a few studies for the synthesis of N-doped carbon dots by microplasma (Wang et al, 2018) (Wang et al, 2015). Wang et al obtained the N-doped carbon dots with an average diameter of 47.31 nm with folic acid and NaHCO 3 as the reactants (Wang et al, 2018).…”

“…There are a few studies for the synthesis of N-doped carbon dots by microplasma (Wang et al, 2018) (Wang et al, 2015). Wang et al obtained the N-doped carbon dots with an average diameter of 47.31 nm with folic acid and NaHCO 3 as the reactants (Wang et al, 2018). Wang et al utilized microplasma as anode and produced N-doped carbon dots with a quantum yield of ~5.1% (Wang et al, 2015).…”