“…The carbon quantum dot (CQD), a quantum-sized carbon material, has drawn great attention as a novel material due to its super hydrophilicity, good biocompatibility, and excellent photoluminescence properties [1,2,3,4]. The light-absorbing properity of CQD render them applicable for photocatalysis, energy conversion, optoelectronic devices, and chemical sensors [5,6,7].…”
The carbon quantum dot (CQD), a fluorescent carbon nanoparticle, has attracted considerable interest due to its photoluminescent property and promising applications in cell imaging and bioimaging. In this work, biocompatible, photostable, and sustainably sourced CQDs were synthesized from byproducts derived from a biorefinery process using one-pot hydrothermal treatment. The main components of byproducts were the degradation products (autohydrolyzate) of biomass pretreated by autohydrolysis. The as-synthesized CQDs had a size distribution from 2.0–6.0 nm and had high percentage of sp2 and sp3 carbon groups. The CQDs showed blue-green fluorescence with a quantum yield of ~13%, and the fluorescence behaviors were found to be stable with strong resistance to photobleaching and temperature change. In addition, it is found that the as-synthesized CQDs could be used for imaging of cells and tumors, which show potential applications in bioimaging and related fields such as phototherapy and imaging.
“…The carbon quantum dot (CQD), a quantum-sized carbon material, has drawn great attention as a novel material due to its super hydrophilicity, good biocompatibility, and excellent photoluminescence properties [1,2,3,4]. The light-absorbing properity of CQD render them applicable for photocatalysis, energy conversion, optoelectronic devices, and chemical sensors [5,6,7].…”
The carbon quantum dot (CQD), a fluorescent carbon nanoparticle, has attracted considerable interest due to its photoluminescent property and promising applications in cell imaging and bioimaging. In this work, biocompatible, photostable, and sustainably sourced CQDs were synthesized from byproducts derived from a biorefinery process using one-pot hydrothermal treatment. The main components of byproducts were the degradation products (autohydrolyzate) of biomass pretreated by autohydrolysis. The as-synthesized CQDs had a size distribution from 2.0–6.0 nm and had high percentage of sp2 and sp3 carbon groups. The CQDs showed blue-green fluorescence with a quantum yield of ~13%, and the fluorescence behaviors were found to be stable with strong resistance to photobleaching and temperature change. In addition, it is found that the as-synthesized CQDs could be used for imaging of cells and tumors, which show potential applications in bioimaging and related fields such as phototherapy and imaging.
“…41,63−65 In addition to the PLQY, a stable PL emission under continuous irradiation is another important requirement for practical applications. 66,67 The PL spectra measured under continuous irradiation showed a stable PL emission intensity, indicating that LGQDs/Mn-LGQDs are resistant to photobleaching (Figure S14).…”
Section: Used For the Optical Band Gap Calculation Is Given Bymentioning
Fluorescent graphene quantum dots
(GQDs) prepared from low-cost
and sustainable precursors are highly desirable for various applications,
including luminescence-based sensing, optoelectronics, and bioimaging.
Among different natural precursors, the unique structural and compositional
variety and the abundance of aromatic carbon in lignin make it a unique
and renewable precursor for the green synthesis of advanced carbon-based
materials including GQDs. However, the inferior photoluminescence
quantum yield of GQDs prepared from natural precursors, including
lignin, limits their practical utility. Here, for the first time,
we demonstrate that the presence of heteroatoms in the innate structure
of lignosulfonate can be leveraged to derive in situ heteroatom-doped
GQDs with excellent photophysical properties. The as-synthesized lignosulfonate-derived
GQDs showed compelling blue fluorescence with a high quantum yield
of 23%, which is attributed to in situ S and N doping as confirmed
by using X-ray photoelectron spectroscopy and Fourier transform infrared
spectroscopy analyses. Assisted by the in situ doping, we further
engineered the lignosulfonate-derived GQDs by incorporating a metal
atom dopant to derive an enhanced quantum yield of 31%, the highest
for any lignin-derived GQDs. Moreover, fundamental photoluminescence
studies reveal the presence of multiple emissive centers, with edge
states acting as dominant emission centers. Finally, we also demonstrate
the applicability of the luminescent, metal- and nonmetal-codoped
lignin-derived GQDs as a highly selective sensor for the sub-nanomolar
level detection of mercuric ions in water.
“…The existing preparation methods of GQD mainly focuses on the hydrothermal cutting method, oxidative cutting carbon fiber method, and electrochemical peeling method [20][21][22]. The hydrothermal cutting method is similar to the oxidative cutting carbon fiber method, and the method is a classic method for preparing GQD, but the method is relatively cumbersome, and a variety of strong acids are introduced [23]. The electrochemical stripping method requires a long time for pre-processing graphite, slow process of post-processing products, and low synthesis yield Ivyspring International Publisher [24].…”
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