Search

Core shell -Streptavidin- nanoparticles were prepared. nanoparticles were synthesized via a sol-gel method. Then, Streptavidin- was covalently bonded to the surface. These core-shell nanoparticles were characterized by steady-state fluorescence spectroscopy and fluorescence scanning. In presence of the silver core, a 2.5-time enhancement of fluorescence intensity was obtained. This result shows that these nanoparticles can be potentially helpful in surface analysis based on biochip. [ABSTRACT FROM AUTHOR]

Abstract: Proteomic microarrays show a wide range of applications for the investigation of DNA–protein, enzyme–substrate as well as protein–protein interactions. Among many challenges to build a viable “protein microarray”, the surface chemistry that will allow to immobilised various proteins to retain their biological activity is of paramount importance. Here we report a chemical functionalisation method allowing immobilisation of oligo-peptides onto silica surface (porous silica, glass, thermal silicon dioxide). Substrates were first derivatised with a monofunctional silane allowing the elaboration of dense and uniform monolayers in highly reproducible way. Prior to the oligo-peptides grafting, this organic layer was functionalised with an amino-polyethyleneglycol. The coupling step of oligo-peptides onto functionalised supports is achieved through activation of the C-terminal function of the oligo-peptides. Chemical surface modifications were followed by FTIR spectroscopy, AFM measurements and fluorescence scanning microscopy. A systematic study of the oligo-peptide grafting conditions (time, concentration, solvent) was carried out to optimise this step. The oligo-peptides grafting strategy implemented in this work ensure a covalent and oriented grafting of the oligo-peptides. This orientation is ensured through the use of fully protected peptide except the terminal primary amine. The immobilized peptides will be then deprotected before biological recognition. This strategy is crucial to retain the biological activity of thousands of oligo-probes assessed on a microarray. [Copyright &y& Elsevier]

Highlights: [•] Preparation of photo functionalizable silica monolith for separation sciences. [•] Rapid, versatile and localizable strategy for functionalization of silica surfaces. [•] Localizable photochemical process applied for the in-line preconcentration and electrokinetic separation of enkephalins. [Copyright &y& Elsevier]

This paper presents a photografting process of monolithic silica capillary columns based on the ene-thiol click chemistry. This study is performed on a “generic” vinyl-functionalized silica monolith ( H min 6 ± 1 μm). The photoclick reaction is investigated using different thiol monomers (octadecanethiol, cysteine and sodium mercaptoethanesulfonate) to prepare capillary columns dedicated to various chromatographic modes (reversed-phase, HILIC and strong cation exchange). Whatever the monomer used, the photografting reaction is achieved in less than 5 min with a relatively high thiol monomer content. This allows preparing highly retentive and efficient monolithic columns while avoiding polymerization and/or column clogging. In addition to the aforementioned properties (duration, versatility, efficiency), this photo-triggered chemical reaction allows addressing several appropriate surface functionalizations inside a single monolithic column in order to prepare nanovolume multimodal capillary columns. A multimodal biphasic monolithic column with a 1 cm length cation-exchange segment followed by a 9 cm length reversed-phase segment (SCX-RP) is prepared through two successive photografting reactions using a UV-mask to localize the reactions. This multimodal biphasic column is investigated using a model sample for the selective fractionation and separation of cationic and neutral compounds and is applied to the on-line preconcentration and separation of β-blockers. [ABSTRACT FROM AUTHOR]