A new optical sensor was developed for rapid screening with high sensitivity for the existence of biogenic amines (BAs) in poultry meat samples. Gold nanoparticles (GNPs) with particle size 11–19 nm function as a fast and sensitive biosensor for detection of histamine resulting from bacterial decarboxylation of histidine as a spoilage marker for stored poultry meat. Upon reaction with histamine, the red color of the GNPs converted into deep blue. The appearance of blue color favorably coincides with the concentration of BAs that can induce symptoms of poisoning. This biosensor enables a semi-quantitative detection of analyte in real samples by eye-vision. Quality evaluation is carried out by measuring histamine and histidine using different analytical techniques such as UV–vis, FTIR, and fluorescence spectroscopy as well as TEM. A rapid quantitative readout of samples by UV–vis and fluorescence methods with standard instrumentation were proposed in a short time unlike chromatographic and electrophoretic methods. Sensitivity and limit of detection (LOD) of 6.59 × 10−4 and 0.6 μM, respectively, are determined for histamine as a spoilage marker with a correlation coefficient (R 2) of 0.993.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-017-2014-z) contains supplementary material, which is available to authorized users.

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Background: Oral cancer is one of the most prevalent cancers. Thymoquinone has a potential therapeutic activity against cancer cells. Aim: to compare the effect of thymoquinone and thymoquinone loaded on gold nanoparticles (GNPs-TQ) as systemic therapeutic agents through intraperitoneal injection for 3&6 weeks after painting of with DMBA 3 times/week for 14w. Material and Methods: This study was carried out on ninety male Syrian golden hamsters (n=90), its age ranged from 6 to 7 weeks, weighting 90-110 gm, purchased from Theodore Blhars Research Institute, Cairo, Egypt. Characterization of GNPs was achieved through using Ultraviolet-Visible spectroscope and transmission electron microscope (TEM). Tissue samples were examined through routine H&E stain, and nuclear factor kappa B cells (NF-κB) immunoreactivity. Results: Formation of spherical and well dispersed gold nanoparticles (GNPs) (27nm). Histopathological evaluation showed retardation of carcinogenesis in hamster buccal pouch and regeneration of striated muscle layers when treated with thymoquinone loaded on gold nanoparticles (GNPs-TQ). These observations were in line with decrease nuclear factor-kappa B expression. Conclusions: GNPs-TQ is a promising chemo-therapeutic agent in regression of carcinogenesis, and improving the general animal health.

Potentiometric equilibrium measurements have been performed at (25.0 ( 0.1) °C and ionic strength I ) 0.1 mol‚dm -3 KNO 3 for the interaction of glycylglycine, glycylhistidine, glycylglycylglycine, glycylhistidylglycine, and Al(III), Ga(III), In(III), and Tl(I) with the biologically important secondary ligands bicine [N,N-bis(2hydroxyethyl)glycine], tricine [N,N,N-tris(hydroxymethyl)methylglycine], PIPES [piperazine-1,4-bis(2-ethanesulfonic acid)], HEPES (N-[2-hydroxyethyl]piperazine-N-[2-ethanesulfonic acid]), and EPPS 4-(2-hydroxyethyl)piperazine 1-propanesulfonic acid in a 1:1:1 ratio. Ternary complexes of the type Al(III)-glycylglycine-guanosine, Al(III)-glycylglycine-guanosine 5′-monophosphate (GMP), Al(III)-glycylglycylglycine-guanosine, Al(III)glycylglycylglycine-GMP, Al(III)-glycylhistidine-guanosine, Al(III)-glycylhistidine-GMP, Al(III)-glycylhistidylglycine-guanosine, Al(III)-glycylhistidylglycine-GMP in a 1:1:1 ratio have been investigated. The experimental conditions were selected such that self-association of the nucleotide and their complexes was negligibly small; that is, the monomeric normal and protonated complexes were studied. The formation of various mixed ligand complexes was inferred from the potentiometric titration curves. Initial estimates of the formation constants of the resulting species and the protonation constants of the different peptides and zwitterionic buffers used have been refined with the SUPERQUAD computer program. Confirmation of the formation of ternary complexes of the type M-P-Z in solution has been carried out using differential pulse polarography, square wave voltammetry, cyclic voltammetry, and UV spectroscopic measurements.