Revisiting carboxylic group functionalization of silica sol-gel materials.

The carboxylic chemical group is a ubiquitous moiety present in amino acids, a ligand for transition metals, a colloidal stabilizer, and a weak acidic ion-exchanger in polymeric resins and given this property, it is attractive for responsive materials or nanopore-based gating applications. As the number of uses increases, subtle requirements are imposed on this molecular group when anchored to various platforms for the functioning of an integrated chemical system. In this context, silica stands as an inert and multipurpose platform that enables the anchoring of multiple chemical entities combined through several orthogonal synthesis methods on the interface.

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation.

Deoxy sugars represent an important class of carbohydrates, present in a large number of biomolecules involved in multiple biological processes. In various antibiotics, antimicrobials, and therapeutic agents the presence of deoxygenated units has been recognized as responsible for biological roles, such as adhesion or great affinity to receptors, or improved efficacy. The characterization of glycosidases and glycosyltranferases requires substrates, inhibitors and analogous compounds.

One-Step Synthesis of Mesoporous Silica Thin Films Containing Available COOH Groups.

Inorganic-organic hybrid mesoporous silica thin films with covalently bonded carboxylic acid groups were synthesized in a one-step procedure, using carboxylic-derivatized alkoxysilanes obtained by photochemical radical thiol-ene addition (PRTEA). The organosilanes were synthesized by clicking mercaptosuccinic or mercaptoacetic thioacids with vinyltrimethoxysilane, using benzophenone as the photoradical initiator. The films were synthesized by evaporation-induced self-assembly of a sol containing a mixture of tetraethoxysilane and different quantities of the organosilanes, without any further treatment after the PRTEA reaction.

Chemisorption of lanthanide ions on succinate-functionalized mesoporous silica: An in situ characterization by fluorescence.

Chemisorption of Eu and Tb on SBA-15 functionalized with succinic groups has been studied by in situ steady-state fluorescence measurements. The enhancement of the emission sensitive bands indicates that both ions adsorb forming inner-sphere surface complexes. Adsorption is a fast process that attains equilibrium in about 5min.

A silica supported tricarbocyanine based pH nanosensor with a large Stokes shift and a near infrared fluorescence response: performance in vitro and in live cells.

We report the synthesis of a near-infrared (NIR) fluorescent pH probe with a remarkable Stokes shift (∼135 nm) based on a tricarbocyanine (Cy-PIP). The fluorescent molecule was anchored to SiO nanoparticles (Cy-PIP@SiO) and is capable of monitoring pH changes within the physiological range (pH 6-8). The Cy-PIP@SiO nanoparticles were successfully internalized by HeLa cells as shown by fluorescence confocal microscopy, while flow cytometry revealed pH fluctuations during the endocytic pathway.

Glyco-nano-oncology: Novel therapeutic opportunities by combining small and sweet.

Recent efforts toward defining the molecular features of the tumor microenvironment have revealed dramatic changes in the expression of glycan-related genes including glycosyltransferases and glycosidases. These changes affect glycosylation of proteins and lipids not only in cancer cells themselves, but also in cancer associated-stromal, endothelial and immune cells. These glycan alterations including increased frequency of β1,6-branched N-glycans and bisecting N-glycans, overexpression of tumor-associated mucins, preferred expression of T, Tn and sialyl-Tn antigen and altered surface sialylation, may contribute to tumor progression by masking or unmasking specific ligands for endogenous lectins, including members of the C-type lectin, siglec and galectin families.

Simple thiol-ene click chemistry modification of SBA-15 silica pores with carboxylic acids.

A straightforward approach for anchoring tailored carboxylic groups in mesoporous SiO2 colloidal materials is presented. The thiol-ene photochemical reaction between vinyltrimethoxysilane precursors and various thiocarboxylic acids which has, click chemistry features (i.e.

Temperature response of luminescent tris(bipyridine)ruthenium(II)-doped silica nanoparticles.

Nanoparticle-based temperature imaging is an emerging field of advanced applications. Herein, the sensitivity of the phosphorescence of tris(bipyridine)ruthenium(II)-doped silica nanoparticles towards temperature is studied. 130 nm size particles were prepared by a modification of Stöber's method, that allows the incorporation of Ru[(bpy)(3)](2+) into the outer particle shell.