A facile hydrothermal method for preparation of fluorescent carbon dots on application of Fe3+ and fingerprint detection

Fluorescent Egg White-Based Carbon Dots as a High-Sensitivity Iron Chelator for the Therapy of Nonalcoholic Fatty Liver Disease by Iron Overload in Zebrafish

Iron overload is the direct cause of many ferroptosis diseases, and it is essential to maintain iron homeostasis. In this paper, we report the Fe³⁺ chelation and therapy of the iron overload nonalcoholic fatty liver disease (NAFLD) by the fluorescent egg white-based carbon dots (EWCDs) obtained through the microwave-assisted pyrolysis method. As a high-sensitivity sensor, EWCDs show a high correlation between fluorescence emission and the concentration of Fe³⁺ (R² = 0.993) in low concentration ranges of 0-25 μM. In vivo and in vitro, the EWCDs show characteristics of high biocompatibility and specific binding of Fe³⁺. As a novel type of the nano-iron-chelator, EWCDs can successfully attenuate the production of lethal reactive oxygen species. EWCDs not only alleviate the endoplasmic reticulum stress response but also regulate the NF-κB signaling pathway downstream of the Nrf2 signaling pathway. EWCDs prevent hepatocyte apoptosis, regulate fatty acid metabolism, and alleviate inflammation. Ultimately, they alleviate NAFLD induced by iron overload in zebrafish. This work may provide a new idea and method for the application of carbon dots in the field of disease detection and treatment.

Metal Ion Detection by Carbon Dots-A Review

Development of economical, sensitive, selective and robust sensors for metal ion sensing is always fascinating for a chemist because traditional routs for their detection involve complicated instrumentation and critical sample preparation procedures. A large number of metal ion detectors including carbon dots (CDs) have been reported for sensitive and selective detection of metal ions. This review comprehensively explores the use of CDs as metallic cation sensors. CDs are being fabricated from variety of carbon sources by employing various synthetic channels. CDs are proved to be efficient colorimetric and fluorimetric detectors due to surface oxygen moieties which are responsible to co-ordinate with metal ions. Doping of CDs with hetero atom such as N, S, B etc. may further enhance their activity toward metal detection. Therefore, designing of CDs having selective sensing properties with low detection limits has gained significant interest.HighlightsCDs have gained much attention as chemical sensors due to their dynamic features i.e. less toxicity, stability, solubility in various solvents, absorption in UV/Vis. region, fluorescence and tunable physico-chemical properties.These are coast effective, sensitive and selective colorimetric and fluorimetric metal ion sensors.Detection of metal ions by CDs involves different mechanisms such as complexation, aggregation, electron transfer, inner filter effect etc.LOD data is an evidence of their greater efficiency.

Fluorescent ZnO quantum dots synthesized with urea for the selective detection of Cr6+ ion in water with a wide range of concentrations

Nearly monodisperse Zinc oxide (ZnO) quantum dots (QDs) displayed yellow fluorescence were synthesized using urea as dispersant. In this paper, urea-ZnO QDs were used as fluorescent probe to detect Cr⁶⁺ in solution. The emission from the as-synthesized urea-ZnO QDs is selectively quenched when Cr⁶⁺ ions were added. Moreover, there are two linear relationships between the quenching of fluorescence intensity and the Cr⁶⁺ concentrations ranging from 4 μM to 1000 μM, with the detection limit for Cr⁶⁺ at 19.53 nM (on basis of 3σ/slope criterion). The quenching of fluorescence is attributed to aggregation of the QDs and charge transfer between the QDs and Cr⁶⁺ by measurements of transmission electron microscopy (TEM) images, UV-visible absorption spectra and fluorescence lifetime.