A coumarin based chemosensor for selective determination of Cu (II) ions based on fluorescence quenching

Microalgae biochar-derived carbon dots and their application in heavy metal sensing in aqueous systems

“…At low concentrations (0 to 5 μM), the Stern-Volmer plot for the 417 MAB-Cdots/Cu 2+ quenching is linear, whereas Ni 2+ and Pb 2+ kept the non-linear downward 418 behaviour. In Stern-Volmer plots, linearity deviations may be associated with the quencher, 419 diffusion properties or the local concentration of the quencher around the quenching sites (Ke 420 et al, 2018;Warrier and Kharkar, 2018). Therefore, the affinity of the heavy metal ions for carboxylic and phenolic OH groups are responsible for some of the MAB-Cdot fluorescence quenching.…”

“…In all cases, the relationship between fluorescence quenching and the metal ions concentration were nonlinear 306 with a downward curvature. Such non-linear Stern-Volmer curves are characteristic of pure 307 collisional quenching where some of the fluorophores/quenching sites are less accessible than 308 others (Ke et al, 2018;Warrier and Kharkar, 2018). Thus, the MAB-Cdot Stern-Volmer 309 plots indicate a system having accessible and inaccessible quenching sites.…”

“…Cdots have high solubility, outstanding photostability, favourable biocompatibility and low toxicity. In recent years, these materials have been fundamental in developing novel 63 sensing methods for detecting different types of pollutants such heavy metal ions (Gao et al, 64 2017;Nair et al, 2017;Warrier and Kharkar, 2018). 65…”

A Coumarin-Based Fluorescence Probe for Selective Recognition of Cu2+ Ions and Live Cell Imaging

“…Due to their strong fluorescence emission, efficient cell permeation, large Stokes shift, and a structure that can be easily modified, coumarin is an attractive starting material [28][29][30][31][32][33]. Besides, the carbonyl group of coumarin can take part in the coordination with metal ions.…”

Sensitive fluorescent assay for copper(ii) determination in aqueous solution using quercetin–cyclodextrin inclusion

“…Thousands of uorescent sensors for copper ions have been reported. [11][12][13][14][15] But the majority of the uorescent probes are synthesized by organic reaction with some toxic reagents and cumbersome process, only few uorescent probes come directly from natural products. It is reported that quercetin, biochanin A and isorhamnetin could act as uorescent probes for detecting copper ions with good selectivity and high sensitivity.…”