Resolving variable cell viability-induced false negative: Accurate and high-contrast fluorescence diagnosis of cancer enabled by dual organelle targeting and multiple microenvironmental parameters responsive versatile carbon dots

Organelle imaging with carbon dots: strategies, challenges, and perspectives

“…CDs with positive charges on their surface can be localized in mitochondria and endoplasm reticulum, or mitochondria and nucleolus, simultaneously. 71,95,96 Besides, negatively charged CDs decorated with citric acid could also target mitochondria, which was driven by the affinity between citric acid and mitochondria. 97 If this affinity can be validated widely, there will be another approach towards intrinsic mitochondria-targeting CDs.…”

“…11,26,95,102 In addition, many CDs are decorated with similar surface chemistry but target different organelles. 13,69,72,96 Moreover, there are also investigations in which CDs prepared from different precursors and possessing different surface chemistry/charge, hydrophilicity, and size could target the same organelle. 28,46,73,90,120 Thus, the organelle selectivity of intrinsic organelle-targeting CDs needs to be improved (Fig.…”

Green Fluorescent Carbon Dots with Critically Controlled Surface States: Make Silk Shine via Feeding Silkworms

“…Among the reported additives, carbon dots (CDs), a new type of zero-dimensional carbon nanoparticles with excellent optical properties and good biocompatibility, have shown unique advantages beyond their counterparts. , The synthetic routes of CDs include “top-down” and “bottom-up” approaches, and the latter has been adopted more frequently in recent years. − The precursors for CDs include various biomass, small molecules, macromolecules, and polymers. − In the family of fluorescent materials, CDs have better photostability and chemical stability than organic dyes and possess lower biotoxicity and easier degradation than metal-based quantum dots/metal oxide nanoparticles. − Moreover, the structure of precursors, reactant ratio, solvent, temperature, and time can be finely adjusted to regulate the fluorescence emission wavelength, quantum yield, particle size, and surface functional groups of CDs. − Although CDs are commonly used in LED lighting, biosensing, imaging, and fluorescence analyses, their tunable fluorescence properties and low toxicity make it possible to produce on a large scale for feeding silkworms to obtain fluorescent silk. − So far, there are only several reports on raising silkworms with CDs. In 2019, blue fluorescent CDs were fed to silkworm to obtain modified silk with increased mechanical properties and intrinsic fluorescence, but the fluorescence of such silk could only be seen under a laser confocal microscope .…”

Rational Design of Orange-Red Emissive Carbon Dots for Tracing Lysosomal Viscosity Dynamics in Living Cells and Zebrafish

“…In comparison, carbon dots (CDs) are commonly synthesized from simple solvothermal or hydrothermal methods and the microwave-assisted method, and they often show splendid fluorescence properties, highly efficient fluorescence emission, low cytotoxicity, good biocompatibility, and excellent photostability. − Therefore, viscosity-sensitive CDs are considered promising candidates for monitoring viscosity dynamics in cells. Several CDs have been currently reported for measuring the viscosity of biological systems. − For example, Sun et al prepared lysosome-targeting CDs from 6-aminobenzo­[ c ]­[1,2]­oxaborol-1­(3H)-ol and tartaric acid, and the CDs exhibited a noticeable polarity and viscosity-sensitive emission and could be utilized in the discrimination of normal cells from cancer cells. Although they are viscosity-sensitive, almost all of them emit green or yellow fluorescence, which not only have strong autofluorescence but also might suffer from serious photodamage to tissues, severely limiting their applications in the biomedical field. , Gao et al used neutral red (NR) and l -cysteine as precursors to prepare l -CQDs, which showed long-wavelength emission and were applied for Golgi apparatus-targeting imaging.…”