Photoactivatable Cross-Linked Polyacrylamide for the Site-Selective Immobilization of Antigens and Antibodies

Abstract

This paper describes the synthesis, characterization, and photochemical behavior of a new light-activated material for the photoimmobilization of antigens. The material is a derivative of cross-linked polyacrylamide that incorporates photoactive o-nitrobenzyl carbamates. When irradiated, the polymer undergoes a photochemical rearrangement to produce primary amines that can be used as molecular attachment sites. We monitored the photoconversion of thin (1-2 µm) polymer films that were deposited on silicon wafers or fused silica substrates using FT IR spectroscopy and UV-vis spectroscopy. To produce patterned polymer-modified substrates, we irradiated the material using a photolithographic mask. This process yielded 10-µm lines of photogenerated amines, to which an amine-reactive antigen (2,4,6-trintrobenzenesulfonic acid) was covalently bound. When we used this antigen-patterned substrate in a competitive fluorescence immunoassay containing tetramethylrhodamine-labeled anti-2,4-dinitrophenyl antibodies and 2,4-dinitrophenol, concentrations of 2,4-dinitrophenol as low as 2.3 µg/mL were detectable.

Novel cell patterning using microheater‐controlled thermoresponsive plasma films

“…Several groups have recently explored the use of dynamic stimulus-responsive surface chemistries for cell patterning to overcome those obstacles. Approaches include thermo-active, 7,9 electrical-active, 8 and photo-active 10 chemistries. In general, all of these chemistries operate under the same principle: they can be switched from a state that prevents cell attachment to a state that promotes it.…”

Hydrogel Nanofilms for Biomedical Applications: Synthesis via Polycondensation Reactions

“…A value of 56 pmol · cm −2 was found. Since there was no additional red shifted emission in the fluorescence spectrum (for spectrum, see Supporting Information) it was concluded that the density of the primary amines is rather low 43, 44. These data suggest a ratio between amino groups and carboxylic acid groups of 1:5.…”

Effect of Constraints on Swelling of Polymer Networks

“…Cross-linked polymer films are encountered in practice in various forms, such as protective organic coatings cross-linked in the course of film formation, stimuliresponsive materials for sensors and other devices, or electroactive layers. [21][22][23][24] Such films are excellent candidates for smart surfaces with sensing and actuating characteristics. The selection of the suitable Gibbs energy function is the first step.…”