Bottom-up synthesis and structural design strategy for graphene quantum dots with tunable emission to the near infrared region

Huang, Dapeng; Zhou, Haifeng; Wu, Yaqiang; Wang, Tao; Sun, Leilei; Gao, Peng; Sun, Yuming; Huang, Huining; Zhou, Guangjun; Hu, Jifan

doi:10.1016/j.carbon.2018.10.047

Cited by 69 publications

(38 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The bottom-up approach generally includes microwave method [73,[85][86][87], molecular carbonization [88][89][90], and electron beam irradiation (EBI) methods [91,92]. Generally, small molecules [93,94] such as citric acid (CA) [95][96][97], amino acid [98,99], phenyl compounds [91,[100][101][102][103], or small molecule sugar [104][105][106] are used as the starting material.…”

Section: Bottom-up Strategymentioning

confidence: 99%

Synthesis of graphene quantum dots and their applications in drug delivery

et al. 2020

View full text Add to dashboard Cite

This review focuses on the recent advances in the synthesis of graphene quantum dots (GQDs) and their applications in drug delivery. To give a brief understanding about the preparation of GQDs, recent advances in methods of GQDs synthesis are first presented. Afterwards, various drug delivery-release modes of GQDs-based drug delivery systems such as EPR-pH delivery-release mode, ligand-pH delivery-release mode, EPR-Photothermal delivery-Release mode, and Core/Shell-photothermal/magnetic thermal delivery-release mode are reviewed. Finally, the current challenges and the prospective application of GQDs in drug delivery are discussed.

show abstract

Section: Bottom-up Strategymentioning

confidence: 99%

Synthesis of graphene quantum dots and their applications in drug delivery

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The first approach is based on the breakdown of large graphite materials in smaller carbon-based materials [16]. However, bottom-up methods, such as microwave-assisted processes [17][18][19][20], appear to be the most widely used for the preparation of CDs, which consist of the synthesis of CDs from smaller carbon precursors (small organic molecules) [21,22]. Among these, citric acid (CA) is one of the most used [17,[23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Environmental Impact and Efficiency of N-Doping Strategies in the Synthesis of Carbon Dots

Christé

Silva

2020

Materials

View full text Add to dashboard Cite

The efficiency and associated environmental impacts of different N-doping strategies of carbon dots (CDs) were evaluated. More specifically, N-doped CDs were prepared from citric acid via two main synthesis routes: Microwave-assisted hydrothermal treatment with addition of N-containing small organic molecules (urea and ethylenediamine (EDA)); and microwave-assisted solvothermal treatment in N-containing organic solvents (n,n-dimethylformamide (DMF), acetonitrile and pyridine). These syntheses produced CDs with similar blue emission. However, XPS analysis revealed that CDs synthesized via both hydrothermal routes presented a better N-doping efficiency (~15 at.%) than all three solvothermal-based strategies (0.6–7 at.%). However, from the former two hydrothermal strategies, only the one involving EDA as a nitrogen-source provided a non-negligible synthesis yield, which indicates that this should be the preferred strategy. This conclusion was supported by a subsequent life cycle assessment (LCA) study, which revealed that this strategy is clearly the most sustainable one from all five studied synthesis routes.

show abstract

“…From the methods of obtaining GOQDs two approaches can be distinguished: Firstly, the top-down approach, which means breaking larger flakes/particles usually by applying ultra-sonication with additional filtration (precursors can include: graphite [18], cellulose [19], or coal [20]). Secondly, the bottom-up approach by carbonization of carbon rich molecules or polymers, e.g., poly(3-alkylthiophenes) via oxidative polymerization [21], citric acid via microwave assisted synthesis [22], eco-friendly solvothermal process by autoclaving in ethylene glycol under 180 • C for 20 h [23], or microwave pyrolysis of poly(ethylene glycol) and saccharide (glucose, fructose) [24]. The possibility of tuning the optical, electrical, and hence opto-electrical properties permits the use of GOQDs for biological imaging, as opto-electrical single-photon detectors [25,26].…”

Section: Introductionmentioning

confidence: 99%

Unraveling Origins of EPR Spectrum in Graphene Oxide Quantum Dots

et al. 2020

View full text Add to dashboard Cite

Carbon nanostructures are utilized in a plethora of applications ranging from biomedicine to electronics. Particularly interesting are carbon nanostructured quantum dots that can be simultaneously used for bimodal therapies with both targeting and imaging capabilities. Here, magnetic and optical properties of graphene oxide quantum dots (GOQDs) prepared by the top-down technique from graphene oxide and obtained using the Hummers’ method were studied. Graphene oxide was ultra-sonicated, boiled in HNO3, ultra-centrifuged, and finally filtrated, reaching a mean flake size of ~30 nm with quantum dot properties. Flake size distributions were obtained from scanning electron microscopy (SEM) images after consecutive preparation steps. Energy-dispersive X-ray (EDX) confirmed that GOQDs were still oxidized after the fabrication procedure. Magnetic and photoluminescence measurements performed on the obtained GOQDs revealed their paramagnetic behavior and broad range optical photoluminescence around 500 nm, with magnetic moments of 2.41 µB. Finally, electron paramagnetic resonance (EPR) was used to separate the unforeseen contributions and typically not taken into account metal contaminations, and radicals from carbon defects. This study contributes to a better understanding of magnetic properties of carbon nanostructures, which could in the future be used for the design of multimodal imaging agents.

show abstract

Bottom-up synthesis and structural design strategy for graphene quantum dots with tunable emission to the near infrared region

Cited by 69 publications

References 78 publications

Synthesis of graphene quantum dots and their applications in drug delivery

Synthesis of graphene quantum dots and their applications in drug delivery

Evaluation of the Environmental Impact and Efficiency of N-Doping Strategies in the Synthesis of Carbon Dots

Unraveling Origins of EPR Spectrum in Graphene Oxide Quantum Dots

Contact Info

Product

Resources

About