Silica-coated graphene compared to Si-CdSe/ZnS quantum dots: Toxicity, emission stability, and role of silica in the uptake process for imaging purposes

Advances in Structural Modifications and Properties of Graphene Quantum Dots for Biomedical Applications

“…Size-tunable optical properties of GQDs are harnessed for tagging biomolecules for their in vitro and in vivo imaging. The possibility of using GQDs as fluorophores has been demonstrated by labeling a variety of cell types such as neuroendocrine PC12 cells, murine alveolar macrophage cells (MH-S), human cervical carcinoma HeLa cells, human hepatic cancer cells (Huh7), MCF-7 stem cells including neural stem cells, pancreas progenitor cells, and neurosphere cells, some of which have been discussed below. ,,, …”

“…The possibility of using GQDs as fluorophores has been demonstrated by labeling a variety of cell types such as neuroendocrine PC12 cells, murine alveolar macrophage cells (MH-S), human cervical carcinoma HeLa cells, human hepatic cancer cells (Huh7), MCF-7 stem cells including neural stem cells, pancreas progenitor cells, and neurosphere cells, some of which have been discussed below. 7,8,15,18 Rajender et al 115 synthesized edge-controlled and highly fluorescent few-layer GQDs-1 and GQDs-2 using solvents of DMSO and DMF, respectively, using the GO precursor. These GQDs containing a high density of armchair edges, oxygenrich functional groups, or surface edge defects and exhibited high PL and QY up to ∼32% and are highly promising for bioimaging applications.…”

“…Other key attributes of GQDs are that they are mostly water-soluble or dispersible, are generally biocompatible with human neural cells, have good photostability, and have low cytotoxicity. − The photophysical properties of GQDs include but are not limited to nanosecond luminescence lifetimes and room temperature phosphorescence or white emission . GQDs are amenable to grafting onto other molecules, dyes, metal complexes, or polymers. , This rich chemistry of GQDs is exploited for the design and fabrication of nanodevices for electrocatalysis, electronics, light-emitting diodes, solar cells, , supercapacitors, − and fuel cells. , They also have a high potential for biomedical applications involving diagnosis, drug delivery, gene delivery, − bioimaging, and biosensing .…”

“…14,15 This kind of high tunability of molecular properties gives firm control over their applications. 16 Other key attributes of GQDs are that they are mostly water-soluble or dispersible, are generally biocompatible with human neural cells, 17 have good photostability, 18 and have low cytotoxicity. 19−21 The photophysical properties of GQDs include but are not limited to nanosecond luminescence lifetimes 22 and room temperature phosphorescence 23 or white emission.…”

Recent advances in synergistic use of GQD-based hydrogels for bioimaging and drug delivery in cancer treatment

“…21,22 A strong control over their uses is provided by the considerable tunability of their molecular characteristics. 23 Other important characteristics of GQDs include their water solubility or dispersibility making sure to be extensively biocompatible with human brain cells, 24 strongly photostable, 25 and low cytotoxic. [26][27][28] GQDs have a variety of photophysical characteristics, including an extremely small excitation lifespan in the range of nanoseconds 29 and room temperature phosphorescence at room temperature which is important in many biomedical applications 30 or white emission which is important for bioimaging.…”