Search

Water-soluble [3]pseudorotaxane with enhanced fluorescence emission was successfully constructed and applied in cell imaging and photodynamic cancer therapy. [ABSTRACT FROM AUTHOR]

A "three‐components" supramolecular assembly has been fabricated by mixing 2, 2': 6', 2"‐terpyridine attached pillar[5]arene, cyano and triazole bearing alkyl chain and Zn2+ in solvent of CHCl3 and CH3CN. The driving forces for the assembly were believed to be host‐guest and metal chelating interactions as characterized by 1H NMR, UV‐vis and fluorescence spectra. The supramolecular organo‐gel formed upon the concentration of components amount to 1 M. The supramolecular displayed nitrobenzene based explosive sensing capability using picric acid, ortho‐nitrobenzene and phenol as samples. The assembly was most sensitive towards picric acid among the three analytes. The limit of detection for picric acid was determined to be 1.66 × 10−4 M. [ABSTRACT FROM AUTHOR]

Abstract: A fluorescent chemosensor for paeonol based on tetramethoxy resorcinarene tetraoxyacetic acid (TRTA) in hexadecyltrimethylammonium bromide (CTAB) medium was investigated. The fluorescence of TRTA was quenched by paeonol due to the formation of weak fluorescent inclusion complex (Paeonol–TRTA), and the fluorescence quenching (ΔF = F TRTA − F Paeonol–TRTA) was sensitized in CTAB. Under the optimal conditions, the linear range of calibration curve for the determination of paeonol was 0.02–6.40μg/mL. The detection limit estimated and RSD was 12.05ng/mL, 2.57% (n =3, c =1.0μg/mL). The mechanism of determination was discussed by quenching type analysis, absorption spectrum titrations, Benesi–Hildebrand method, fluorescence quantum yield and IR spectra. This method has also been applied for the determination of paeonol in real sample with satisfactory result. [Copyright &y& Elsevier]

A novel fluorescent chemosensor of the derivatives of calix[4]arene (SAX) for Congo red (CR) in methyl-β-cyclodextrin/Triton X-100 synergistic sensitized system was developed. The results showed that the fluorescence intensity of SAX could be quenched by CR, and the fluorescence quenching (∆F = FSAX − FCR-SAX) was synergistic sensitized by methyl-β-CD and Triton X-100. Under the conditions of λex/em = 332/468 nm and pH 7.5, the linear range and the detection limit for CR were found to be 0.040-8.0 μg/mL and 8.9 ng/mL, respectively. The mechanism of determination was discussed by quenching type analysis and sensitizing effect. This method has also been applied for the determination of CR in beef samples with satisfactory results. [ABSTRACT FROM AUTHOR]

A novel surfactant sensitized fluorescent chemosensor for safranine T (ST) based on calixarene-1,3-diacyl hydrazone (CADH) in sodium dodecyl sulfate (SDS) medium was investigated. The fluorescence intensity of CADH was quenched by ST due to the formation of weak fluorescent inclusion complex (ST-CADH), and the fluorescence quenching (Δ F = F CADH − F ST-CADH ) was sensitized in SDS. Under the optimal conditions, the linear range of calibration curve for the determination of ST was 0.02–3.00 μg/m and the detection limit estimated 0.015 μg/mL with RSD 2.2% ( n = 3, c = 1.0 μg/mL). The mechanism of determination was discussed with the fluorescence quenching type, the inclusion of CADH with ST and surfactant sensitized effect. This method has been applied for the detection of ST in real samples with satisfactory results. [ABSTRACT FROM AUTHOR]