A novel highly selective FRET sensor for Fe(III) and DFT mechanistic evaluation

Sodium vanadates doped boron phosphorus graphene quantum dots: A novel nanosensor for the fluorescence detection of rutin

Rutin, a naturally occurring flavonoid compound, possesses notable antioxidant properties along with anti-inflammatory and antiviral effects. This research aimed to improve the selectivity and high fluorescence behavior of novel nanomaterial BPGQDs@NaV, which was synthesized by hydrothermal methods. Through comprehensive characterization utilizing TEM, SEM, XRD, EDS, FT-IR, UV-Vis, TCS-PC, and XPS techniques, the prepared BPGQDs, NaV, and BPGQDs@NaV were thoroughly examined. The resulting BPGQDs@NaV nanomaterials demonstrated stable, reproducible fluorescence responses and exhibited selective recognition capabilities towards rutin. The sensor developed in this study displayed remarkable performance in rutin detection, offering a broad linear range from 5 to 110 nM and an outstanding detection limit of 15.16 nM. A computational study was used to examine energy, stability, band gap, and how rutin interacted with the BPGQDs@NaV, and it also favored the detection mechanism. A portable smartphone-based sensor was also developed for the detection of rutin.

A sensitive "turn-on" Schiff-base fluorescent probe for the selective detection of Fe3+ and bio-imaging

A novel Schiff-base fluorescent probe, 4-(N-(2- hydroxyl-1-naphthalymethylimino)-ethylamino) -7-nitro-1,2,3-benzoxadiazole (HENB) was synthesized and utilized for spectral sensing of Fe3+ ions at neutral pH. The binding of Fe3+ to HENB in C2H5OH-HEPES buffer (1:1 v/ v, 25 mM, pH 7.2) resulted in a pronounced emission enhancement at 530 nm, which is possibly due to the inhibition of photo-induced electron transfer (PET) process as well as the chelation enhanced fluorescence (CHEF) effect. HENB shows good selectivity and sensitivity toward Fe3+ with the detection limit as low as 4.51 nM. Test strips made of HENB was used for rapid "naked-eye" detection of Fe3+ ions in aqueous medium. Moreover, HENB was successfully applied in fluorescence imaging of exogenous and endogenous Fe3+ in live Hela cells as well as zebrafish. Importantly, HENB is capable of effectively monitoring the variations of Fe3+ in living cells during ferroptosis process.

Highly selective, sensitive and biocompatible rhodamine-based isomers for Al3+ detection: A comparative study

Selective detection of a metal ion with high selectivity is of great importance to understand its existence and its role in many chemical and biological processes. We report here the synthesis, characterization and Al3+ sensing properties of two rhodamine-based isomers, (E)-2-((2-(allyloxy)benzylidene)amino)ethyl)-3',6'-bis(ethylamine)-2',7'-dimethylspiro[isoindoline-1,9'-xanthen]-3-one (L-2-oxy) and (E)-2-((4-(allyloxy)benzylidene)amino)ethyl)-3',6'-bis(ethylamine)-2',7'-dimethylspiro[isoindoline-1,9'-xanthen]-3-one (L-4-oxy). L-2-oxyand L-4-oxy show pink coloration, significant enhancement in absorbance at 530 nm and fluorescence intensity at 553 nm in the presence of Al3+ among several cations. Quantum yield and lifetime of the probes increase in the presence of Al3+. LOD values have been determined as low as ∼1.0 nM for both the isomers. DFT study suggests that the cation induces opening of spirolactam ring resulting in the changes of the rhodamine dyes. Additional reason could be Chelation Enhanced Fluorescence (CHEF) effect due to the subsequent chelation of the metal ion. Between two isomers, L-2-oxy displays better sensing ability towards Al3+ in terms of fluorescence enhancement, limit of detection, lifetime enhancement. Both the probes have been utilized in cell imaging studies using rat skeletal myoblast cell line (L6 cell line).