Site-Specific Immobilization of DNA in Glass Microchannels via Photolithography

Abstract

For the first time, a microchannel was photochemically patterned with a functional linker. This simple method was developed for the site-specific attachment of DNA via this linker onto silicon oxide surfaces (e.g., fused silica and borosilicate glass), both onto a flat surface and onto the inside of a fused silica microchannel. Sharp boundaries in the micrometer range between modified and unmodified zones were demonstrated by the attachment of fluorescently labeled DNA oligomers. Studies of repeated hybridization-dehybridization cycles revealed selective and reversible binding of cDNA strands at the explicit locations. On average, approximately 7 x 10(11) fluorescently labeled DNA molecules were hybridized per square centimeter. The modified surfaces were characterized with X-ray photoelectron spectroscopy, infrared microscopy, static contact angle measurements, confocal laser scanning microscopy, and fluorescence detection (to quantify the attachment of the fluorescently labeled DNA).

Copper-Free Click Biofunctionalization of Silicon Nitride Surfaces via Strain-Promoted Alkyne–Azide Cycloaddition Reactions

“…Patterning experiments were performed according to the literature. 84 Briefly, patterning experiments were performed in a glovebox (MBraun MB200G with a gas purification unit MBraun MB20G) under an argon atmosphere and a content of H 2 O and O 2 each below 0.1 ppm. Degassed TFE was added to freshly etched surface until a thin liquid layer formed; afterward, an electron microscopy grid (SEM F1, Au, Gilder Grids) with various mesh numbers was placed on top, followed by a fused quartz cover.…”

Covalent Surface Modification of Oxide Surfaces

“…The confocal image of a modified capillary with an inner diameter of 100 μm indicates the transition distance. e) Covalent functionalization with a non‐fluorescent oligo‐DNA, which is then used to hybridize with fluorescently labeled DNA, to show the possibility of local hybridization 152a. f) Spatially selective immobilization of two different DNA fragments has been used to position two enzymatic DNA–protein hybrids that are part of an enzymatic cascade reaction 152b…”

A true theranostic approach to medicine: Towards tandem sensor detection and removal of endotoxin in blood

“…Both molecules possess a highly reactive trichlorosilyl function (Cl 3 Si-R) for covalent siloxane anchorage (-OSi(OH) 2 -R) to the quartz substrate. OEG-TTTA cross-linker also bears a distal trifluoroethyl ester (TFEE) functionalizable group for the subsequent, site-specific covalent immobilization of PMB (Fryxell et al, 1996;Vong et al, 2009;Biesta et al, 2012;Latham and Williams, 2006). MEG-TFA is a shorter 'diluent' molecule, whose role is to space out OEG-TTTA cross-linking residues within an otherwise congested assembly, thereby enhancing TFEE head function reactivity/accessibility for PMB attachment (Fryxell et al, 1996).…”