Immobilization of Amine-Modified Oligonucleotides on Aldehyde-Terminated Alkanethiol Monolayers on Gold

Abstract

Chemistry is described for the fabrication of DNA arrays on gold surfaces. Alkanethiols modified with terminal aldehyde groups are used to prepare a self-assembled monolayer (SAM). The aldehyde groups of the monolayer may be reacted with amine-modified oligonucleotides or other amine-bearing biomolecules to form a Schiff base, which may then be reduced to a stable secondary amine by treatment with sodium cyanoborohydride. The surface modifications and reactions are characterized by polarization modulation Fourier transform infrared reflection absorption spectroscopy (PM-FTIRRAS), and the accessibility, binding specificity, and stability of the DNA-modified surfaces are demonstrated in hybridization experiments.

Development of a Screening Assay for Ligands to the Estrogen Receptor Based on Magnetic Microparticles and LC-MS

“…For example, the amount of ER-α immobilized on the aldehyde functionalized magnetic particles increased ~11-fold as the initial concentration of ER-α was increased from 30 to 400 μg/mL. This observation is consistent with the results of previous studies [20,21] and was probably due to protein-protein coupling in addition to proteinmagnetic particle coupling. Additional experiments were carried out using a 600-fold molar excess of coupling reagents (data not shown).…”

“…The immobilization of ER-α on aldehyde functionalized magnetic particles occurred through the formation of Schiff's bases with protein primary amines and was made irreversible by reduction by NaCNBH 3 for 14 h [19]. Carboxylic acid functionalized magnetic particles were activated by EDC for immobilization of protein amino groups through the formation of amide bonds, which was carried out during incubation with ER for 20 h [20]. A 250-fold excess of EDC or NaCNBH 3 was used relative to the ER, and the reactions were carried out in 1.5 mL Eppendorf tubes using gentle rotation.…”

Formation of aldehyde‐ and carboxy‐terminated self‐assembled monolayers on SiO2 surfaces

“…[1 -3] Among the various functional groups found to be effective, aldehyde (CHO) and carboxy (COOH) groups are particularly important because of their chemical reactivity to minerals, biomolecules, and metal ions. [3 -10] Although there have been numerous reports describing the formation of CHO- [4,5] and COOH-terminated alkanethiol SAMs [9 -11] on gold surfaces, there have been fewer studies on organosilane SAMs terminated with CHO [3,6,7] and COOH [8,12 -16] groups on SiO 2 or other oxide surfaces in spite of the practical advantages they offer. In particular, there have only been a limited number of papers describing the formation of COOH-terminated organosilane SAMs on SiO 2 or other oxide surfaces.…”

Preparation of Bio-Functionalized Surfaces with an Electrochemically Active Silane Presenting Concealed Aldehyde

“…The limitation of the use is a lack of stability of aldehyde group during synthesis, storage, and attachment process. 2,3 To overcome the drawback, it is desirable that the group is protected before use and even during the surface modification process. After the modification the group is on-demand deprotected by external stimuli.…”