A closer look at photo-induced crosslinking of thymine polymers using time FT-IR and chemometric analysis

KRIS MCDONOUGH, SANTIAGO A. BORTOLATO, KATELYN THOMAS, NANCY LEE, RICHARD W. GURNEY, AND DEBORA MARTINO

Lusiana

Exposición; 245th ACS National Meeting & Exposition; 2013

American Chemical Society

In recent years there has been a great interest in the design and construction of micro and nanostructures having functional responses to external stimulus (pH, temperature, light), especially for use as microsensors and controlled release systems. This study used copolymers containing thymine residues, 4-vinylbenzyl thymine (VBT) and ionic styrene derivatives, 4-vinylbenzyl triethyl ammonium chloride (VBA). As what happens naturally in the DNA chains, UV irradiation induces the formation of cyclobutane dimers between neighboring thymine residues, resulting in three-dimensional crosslinking of copolymer chains. The photo-dimerization kinetics for copolymers of varying composition has been investigated using grazing-angle specular-reflectance infrared spectroscopy, complemented by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) methods. The study allows the sequential estimation of the contribution to the total signal due to different species, than can be used to calculate the crosslinking rate.