Microwave irradiation was used to obtain a di-Schiff base type crosslinked chitosan dibenzocrown ether (CCdBE) via the reaction between the -NH(2) and -CHO groups in chitosan and 4,4'-diformyldibenzo-18-c-6, respectively. The structure of the synthesized compound was characterized by elemental analysis, solid state 13C-NMR and FT-IR spectra analysis. The results showed that the mass fraction of...

Environmental pollution caused by heavy metal ions has become a major health problem across the world. In this study, selective colorimetric sensor based on starch functionalized silver nanoparticles (St-Ag NPs) for rapid detection of Hg2+ in real samples was developed. The environmentally friendly green approach utilized to synthesize (St-AgNPs). A multi-technique involving UV-Vis absorption s...

A facile supported liquid membrane (SLM) system for the selective and efficient transport of silver ion is introduced. The SLM used is a thin porous polyvinyldifluoride membrane impregnated with hexathia-18-crown-6 (HT18C6) dissolved in nitrophenyloctyl ether. HT18C6 acts as a specific carrier for the uphill transport of Ag+ ion as its picrate ion paired complex through the SLM. In the presence...

The mercury ion (Hg2+) is regarded as one of the toxic cations that extremely harmful and dangerous to human health environment. With this growing awareness, it imperative facile rapid sensing systems developed for detection Hg2+. Due excellent sensitivity selectivity, graphene quantum dots (GQDs), a zero-dimensional carbon nanomaterial, are attracting attention researchers promising candidates...

A DNA-Au NP probe for sensing Hg2+ using the formation of DNA-Hg2+ complexes through thymidine (T)-Hg2+ -T coordination to control the negative charge density of the DNA strands-thereby varying their structures-adsorbed onto Au NPs.

Mercuric reductase, MerA, is a key enzyme in bacterial mercury resistance. This homodimeric enzyme captures and reduces toxic Hg2+ to Hg0, which is relatively unreactive and can exit the cell passively. Prior to reduction, the Hg2+ is transferred from a pair of cysteines (C558' and C559' using Tn501 numbering) at the C-terminus of one monomer to another pair of cysteines (C136 and C141) in the ...

The development of fluorescent sensors for Hg2+ has attracted much attention due to the well-known adverse effects of mercury on biological health. In the present work, the optical properties of two newly-synthesized Hg2+ chemosensors based on the coumarin-rhodamine system (named Pro1 and Pro2) were systematically investigated using time-dependent density functional theory. It is shown that Pro...

The amphibian urea transporter (fUT) shares many properties with the mammalian urea transporters (UT) derived from UT-A and UT-B genes. The transport of urea by fUT is inhibited by the mercurial agent p-chloromercuribenzenesulfonic acid (pCMBS). We found that in oocytes expressing cRNA encoding fUT, a 5-min preincubation in 0.5 mM mercury chloride (HgCl2) also significantly reduced urea uptake....

arthrobotrysamerospora (atcc 34468) produced glucoamylase in a semi-synthetic medium containing starch as a sole carbon source. polyacrylamide gel electrophoresis of crude glucoamylase showed three isoenzymes. they were designated as glu i, glu ii and glu iii according to their electrophoretic mobility. these iso-glucoamylases were purified by column chromatography using deae-sephadex a-50. the...

Expression cDNA clones of alpha1B-1 or alpha1E-3 subunits coding for human neuronal N-(Cav2.2) or R-subtype (Cav2.3) Ca2+ channels, respectively, was combined with alpha2-bdelta and beta3-a Ca2+ channel subunits, and transfected into human embryonic kidney cells for transient expression to determine whether specific types of neuronal voltage-sensitive Ca2+ channels are affected differentially b...