RESUMO
Fluorescent siderophore pyoverdin (PVD) was produced from a soil isolate Pseudomonas monteilii strain MKP 213. The PVD was purified near to homogeneity and applied for the fluorescent chemosensing of various antibiotics in aqueous solution (pH=7.0). Upon addition of ciprofloxacin, PVD showed new UV-vis absorption bands at 252 and 321nm due to an internal charge transfer mechanism. Also, the addition of ciprofloxacin induced a highly selective fluorescence enhancement of PVD with a 13nm blue shift from 458 to 445nm. The combination of a long peptide chain along with the chromophore unit of PVD generates a converging cleft for ciprofloxacin recognition with LOD and LOQ of 7.13µM and 21.6µM, respectively without interference from other studied antibiotics. The association constant (Ka) of PVD with ciprofloxacin was calculated to be as low as 1.40×10(5)M(-1) using Benesi-Hildebrand plot depicting its significance in detection. The pharmaceutical tablet analysis measures the sensing with negligible matrix effect and quantitative recovery.
Assuntos
Antibacterianos/análise , Ciprofloxacina/análise , Corantes Fluorescentes/química , Oligopeptídeos/química , Sideróforos/química , Humanos , Limite de Detecção , Células MCF-7 , Pseudomonas/química , Espectrometria de Fluorescência/métodosRESUMO
A fluorescent based receptor (4Z)-4-(4-diethylamino)-2-hydroxybenzylidene amino)-1,2dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (receptor 3) was developed for the highly selective and sensitive detection of Cu(2+) and Zn(2+) in semi-aqueous system. The fluorescence of receptor 3 was enhanced and quenched, respectively, with the addition of Zn(2+) and Cu(2+) ions over other surveyed cations. The receptor formed host-guest complexes in 1:1 stoichiometry with the detection limit of 5 nM and 15 nM for Cu(2+) and Zn(2+) ions, respectively. Further, we have effectively utilized the two metal ions (Cu(2+) and Zn(2+)) as chemical inputs for the manufacture of INHIBIT type logic gate at molecular level using the fluorescence responses of receptor 3 at 450 nm.
Assuntos
Cobre/análise , Etilaminas/química , Fluorescência , Corantes Fluorescentes/química , Lógica , Pirazóis/química , Zinco/análise , Etilaminas/síntese química , Corantes Fluorescentes/síntese química , Estrutura Molecular , Pirazóis/síntese química , Teoria Quântica , Espectrometria de Fluorescência , Espectrofotometria UltravioletaRESUMO
A pyridine based imine-linked chemosensor has been synthesized and evaluated its binding affinity with library of transition metal ions. It has prominent selectivity towards Pb2+ among other metal ions in DMF/H2O (9:1, v/v) solvent system. The 1:1 stoichiometric was confirmed by job's plot and has a binding constant (Ka) = 5.142 × 103 M-1 on fluorescence. A B3LYP/6-31G and B3LYP/LanL2DZ basis sets were employed for optimization of 3 and 3.Pb2+.
RESUMO
Novel substituted phenol-based new symmetrical bis(2-hydroxy-3-isopropyl-6-methyl-benzaldehyde)ethylenediamine (1) has been designed and synthesized. The compound 1 fluorometrically recognized Cu(2+) ion in CH3OH/H2O (90:10, v/v) by exhibiting an increase in emission upon complexation. In addition, Cu(2+) gave rise to a change in colour of the solution of compound 1, which was clearly visible to the naked eye under UV irradiation. The association constant (K) of compound 1 with Cu(2+) ion was computed with the Benesi-Hildebrand plot and Scatchard plot at 43,000 M(-1) and 43,011 M(-1) respectively.