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Given that peroxynitrite (ONOO − ) is profoundly associated with health and diseases, a new fluorescent probe ABT was designed and synthesized for detection of ONOO − . ABT manifested not only ratiometric fluorescence signals simultaneously in response to concentrations of ONOO − (within 10 s), but high selectivity and sensitivity towards ONOO − over other physiological relevant species (detection limit = 26.3 nM). Moreover, ABT worked in a broad pH range with biological relevance. Thus, ABT could be used to quantitative detection of ONOO − concentration and has the potential to efficiently monitor ONOO − in living organisms. [ABSTRACT FROM AUTHOR]

Abstract: A novel fluorescein derivative, synthesized by the reaction of fluorescein hydrazide and 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, was evaluated as a chemoselective metal ion sensor. Addition of Cu2+ to an aqueous solution of the fluorescein derivative resulted in a rapid color change from colorless to deep yellow together with a distinctive change in UV–vis absorption spectrum. However, other common alkali-, alkaline earth-, transition- and rare earth metal ions induced no or minimal spectral changes. The stoichiometry of the reaction and association constant of the fluorescein derivative with Cu2+ are described. Experimental results indicate that the fluorescein derivative could provide a rapid, selective and sensitive response to Cu2+, and could be used as a potential Cu2+ colorimetric chemosensor in aqueous solution. [ABSTRACT FROM AUTHOR]

Abstract: The interaction of curcumin with intravenous immunoglobulin (IVIG) mainly composed of immune gamma globulin (IgG) was studied in vitro by spectroscopic methods including fluorescence spectroscopy and Fourier transformation infrared (FTIR) spectroscopy. Docking was used to calculate the interaction mode between curcumin and IVIG. The binding parameters for the reaction were calculated according to the Sips equation, which suggested that the binding of IVIG to curcumin was characterized by two binding sites with the average affinity constant K o at 1.170×104 M−1 (296K), and it was a non-specific and weak drug–protein interaction. The secondary structure compositions of free IVIG and its curcumin complexes were calculated by the FTIR difference spectra, self-deconvolution, second derivative resolution enhancement and the curve-fitting procedures of amide I band. The observed spectral changes indicate a partial unfolding of the protein structure, but the typical β structural conformation of IVIG is still retained. The average binding distance between curcumin and the chromophore of IVIG (5.57nm) was obtained using the theory of Förster energy transfer. IVIG can serve as transport protein (carrier) for curcumin. [Copyright &y& Elsevier]

Abstract: The interaction of anti-cancer drug Taxol (paclitaxel) with human intravenous immunoglobulin (IVIG) was studied under simulated physiological conditions in vitro by spectroscopic methods including fluorescence spectra and Fourier transformation infrared (FT-IR) difference spectra. Docking was used to calculate the interaction modes between Taxol with IVIG. Transmission electron microscopy (TEM) experiments were carried out to investigate the formation of aggregate and crystal of Taxol in aqueous solution. The binding parameters were calculated according to the Sips procedure. The Taxol–IVIG complexes showed two types of binding with the average affinity constant of 1.776×104 ±1.16 M−1 (n =2, 296 K) and 0.7386×104 ±1.18 M−1 (n =4, 296 K). The molecules of Taxol were mainly located in CDR of Fab regions and Fc regions of IgG. The interaction of IVIG with Taxol was of non-specific and weak drug–protein binding, and it could inhibit Taxol from crystallizing in aqueous solution when the molar concentration ratio of Taxol to IVIG did not exceed 15:1. The content of secondary structure compositions of free IVIG and its Taxol complexes were calculated by the FT-IR difference spectra with its self-deconvolution, second derivative resolution enhancement and the curve-fitting procedures of amide I band. The observed FT-IR spectral changes indicated a partial unfolding of the protein structure in the presence of Taxol in aqueous solution. IVIG can serve as a transport protein (carrier) for Taxol. [Copyright &y& Elsevier]

Herein Pd/Fe 3 O 4 -PEI-RGO nanohybrid was synthesized by dispersion of Pd NPs and Fe 3 O 4 NPs on PEI modified graphene oxide sheets. This nanohybrid was found to possess superior peroxidase-like activity, and could efficiently oxidize 3,3′,5,5′-Tetramethylbenzidine (TMB) by hydrogen peroxide (H 2 O 2 ) to produce a color reaction. Therefore, this provides a sensing platform for the colorimetric detection of H 2 O 2 in solution. The linear range for H 2 O 2 was from 0.5 to 150 μM and the limit of detection was as low as 0.1 μM. Moreover, the nanohybrids have the advantages of facile preservation and rapid separation. More importantly, comparing with the other catalysts (PEI-RGO, Fe 3 O 4 -PEI-RGO and Pd-PEI-RGO), this nanohybrid exhibits the enhanced peroxidase catalytic activity. Thus, it is expected that this nanohybrid could conveniently and efficiently detect H 2 O 2 in the pharmaceutical, environmental and industrial fields. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel water-soluble fluorescent chemosensor based on naphthalene derivate was designed. [•] The fluorescent chemosensor for Al3+ could be synthesized simply. [•] The fluorescent sensor exhibited high selectivity for Al3+ in absolute water media (pH=7.0). [ABSTRACT FROM AUTHOR]

Abstract: Series LiFePO4/C materials have been prepared by a so-called reformative solid-coordination method, which uses citric acid as the coordination agent and carbon source. A monodenate coordination band of –COO-M was proved to form gradually and that would help to disperse Li+ or Fe2+ among the homogeneous gel during the grinding process. Impure phase Fe2P was detected out among the LiFePO4/C composites with increasing annealed temperature. The remnant coating carbon was considered to be the reductive under the pure nitrogen gas. The amounts of carbon, particle size and morphology were investigated in detail and all the results showed to be related to the formation of Fe2P. The electro-conductive Fe2P phase among LiFePO4/C composites acts as important role in increasing electronic conductivity and evidently improves the electrochemical performance of LiFePO4/C including the less polarization phenomenon, comparatively high reversible capability, stable cycling performance and slight trend of less loss of rate capability. [Copyright &y& Elsevier]