A sensitive “ON–OFF” fluorescent probe based on carbon dots for Fe²⁺ detection and cell imaging

Abstract

A sensitive fluorescent probe based on carbon dots has been synthesized by a one-pot hydrothermal method for the rapid detection of intracellular Fe2+.

Carbon dots crosslinked chitosan/cellulose sponge capture of methyl blue by an adsorption process

“…High‐resolution spectra (inset in Figure 1a) showed that the core of CA‐CDs possessed a crystal diffraction stripe and network lattice, which are similar to those of a graphite structure. [ 25 ] As shown in Figure 1b, the main size distribution of CA‐CDs was between 3.8–10.1 nm, and Gaussian fitting provided an average size of approximately 6.5 nm.…”

Recent Progress in Fluorescent Probes For Metal Ion Detection

“…On the one hand, it is difficult to establish a highly specific probe for the detection of Fe 2+ , because the different oxidation states of Fe 2+ and Fe 3+ vary with each other. On the other hand, due to the strong force between paramagnetic Fe 2+ and fluorophore, fluorescence quenching is usually induced, resulting in part of the constructed probes being “on-off” type, which is not easy to observe due to the influence of spontaneous fluorescence of organisms ( Wei et al, 2020 ). Currently, the Fe 2+ fluorescent probes mainly include N-oxides, nitroxyl radicals, endoperoxides, bionic ligands, heavy metals, imines and so on.…”

“…The results show that the addition of Fe 2+ with the probe solution improved the magnetic intensity of fluorescence by 6-fold. Wei et al ( Wei et al, 2020 ) developed a “on-off” fluorescent probe based on a carbon point (CDs), which has been efficiently used to detect Fe 2+ in BSA solution, tap water and living cells ( Figure 4A ). In order to realize real-time detection of unstable ferric divalent ions in living systems, Long et al ( Long et al, 2018 ) designed a fluorescent probe of coumarin by using a unique cyclization reaction.…”

Fluorescent Carbon Dots for Sensitive and Rapid Monitoring of Intracellular Ferrous Ion

“…To our knowledge, although fluorescent CDs have been widely utilized in the detection of intracellular iron ions based on the fluorescence quenching effects of iron ions [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], most of them were developed for the monitoring of trivalent ferric Fe 3+ ions [ 10 , 11 , 12 , 13 , 14 , 15 ]. Few reported CDs have been designed for specific detection of divalent ferrous Fe 2+ ions over ferric ions [ 18 , 19 , 20 ] and successfully applied to monitor the intracellular Fe 2+ ions [ 16 , 21 ]. Ferrous ions enhance oxidative stress by catalyzing the production of reactive oxygen species that induce biochemical signaling processes, leading to degenerative diseases such as cancer, Alzheimer’s disease, and Parkinson’s disease [ 22 , 23 , 24 ].…”