Chemical binding

About: Chemical binding is a research topic. Over the lifetime, 1822 publications have been published within this topic receiving 52516 citations.

Ultrabright dye-loaded spherical polyelectrolyte brushes and their fundamental structure-fluorescence tuning principles

Abstract: Ultrabright fluorescent particles (UFPs) have attracted increasing attention because of their outstanding signal amplification functions. However, there is still an urgent demand for designing novel UFPs with new components or structures as the existing ones can not satisfy the practical requirements due to their inherent disadvantages. Here we propose a novel ultrabright fluorescent particle platform by doping dyes of 5-aminofluorescein (5-AF) into silica core-based spherical poly (acrylic acid) brushes (SiO2@PAA@5-AF) and discuss their fundamental structure-fluorescence tuning principles. A series of brushes with different polymer chain lengths are successfully synthesized and then loaded with 5-AF through chemical binding. The high loading amount, suitable density or distribution, and enhanced quantum yield (QY) of 5-AF due to the amide bond formation with PAA chains on brushes are concluded as the three major reasons for the ultrabrightness of SiO2@PAA@5-AF. Therefore, a 2350 ± 445 times brighter brush particle in comparison to a single quantum dot (QD) is realized, and a 2.1 ± 0.4 times fluorescence improvement of a brush vs. a QD normalized by volume is also achieved when taking the hydrodynamic diameter into consideration (∼300 nm vs. ∼30 nm). Moreover, the excellent tolerance stabilities in normally applied environments and outstanding label effects to form 4-plexed encoded beads are demonstrated as well. The results in this work strongly indicate a promising potential of SiO2@PAA@5-AF as an ultrabright and stable signal amplification tool for biomedical related sensing, labeling, and biodetection.

Assay of chemical binding

Abstract: A method of comparing the binding strengths of a plurality of different ligands to a receptor, in which several micro-cantilever structures (10) are coated with the receptor on at least a part of a surface (13) of each micro-cantilever structure (10). Each micro-cantilever structure (10) is then contacted with a different ligand solution, and the amounts by which the micro-cantilever structures deflect are compared. The deflection may be detected by an optical lever (16,18; 28). The micro-cantilever structures (10) may be in the form of an array, each structure (10) being in a respective well (24), to which ligand solutions are added.

Effects of Chemical Binding on the X-Ray K α 1 , 2 Doublet Lines of Sulphur Studied with a Two-Crystal Spectrometer

Abstract: Ionization curves of the $K{\ensuremath{\alpha}}_{1, 2}$ doublet lines of sulphur have been recorded with the two-crystal spectrometer. Several sulphides and sulphates were used as targets. The effects of the chemical binding on the wave-length, on the ${\ensuremath{\alpha}}_{1}\ensuremath{\rightarrow}{\ensuremath{\alpha}}_{2}$ separation and on the doublet contour were measured. With suitably chosen targets, the wave-length shift of the S $K{\ensuremath{\alpha}}_{1, 2}$ lines from sulphates to sulphides was observed in the process of shifting.

Decreased Binding of 14 C-Homogentisic Acid induced by Ascorbic Acid in Connective Tissues of Rats with Experimental Alcaptonuria

Abstract: ADULTS with alcaptonuria develop a destructive arthritis secondary to the deposition of a melanin-like pigment in their connective tissues, especially skin, tendon and Cartilage (ochronosis). The biochemical steps leading to ochronosis involve the chemical binding of oxidized and/or polymerized derivatives of homogentisic acid (HGA), the metabolite accumulating in the blood in alcaptonuria, to these connective tissues, with subsequent physico-chemical alterations in the properties of collagen1. HGA seems to be converted to an oxidized polymerized derivative through the formation of a labile, oxidized intermediate, benzoquinone acetic acid (BQA). Both steps in this conversion are catalysed by HGA polyphenol oxidase, a copper-requiring enzyme2.