Simultaneous Measurement of the Dissolution Kinetics of Responsive DNA Hydrogels at Multiple Length Scales.

TitleSimultaneous Measurement of the Dissolution Kinetics of Responsive DNA Hydrogels at Multiple Length Scales.
Publication TypeJournal Article
Year of Publication2017
AuthorsSimon AJ, Walls-Smith LT, Freddi MJ, Fong FYi, Gubala V, Plaxco KW
JournalACS Nano
Volume11
Issue1
Pagination461-468
Date Published2017 Jan 24
ISSN1936-086X
Abstract

Recent years have seen increasing study of stimulus-responsive hydrogels constructed from aptamer-connected DNA building blocks. Presumably due to a lack of simple, quantitative tools with which to measure gel responsiveness, however, the literature describing these materials is largely qualitative. In response, we demonstrate here simple, time-resolved, multiscale methods for measuring the response kinetics of these materials. Specifically, by employing trace amounts of fluorophore-quencher labeled cross-linkers and the rheology of entrapped fluorescent particles, we simultaneously measure dissolution at molecular, hundred-nanometer, and hundred-micron length-scales. For our test-bed system, an adenine-responsive hydrogel, we find biphasic response kinetics dependent on both effector concentration and depth within the gel and a dissolution pattern uniform at scales longer than a few times the monomer-monomer distance. Likewise, we find that, in agreement with theoretical predictions, dissolution kinetics over the hundred nanometer length scale exhibit a power-law-like dependence on the fraction of disrupted cross-links before a distinct crossover from solid-like to liquid-like behavior.

DOI10.1021/acsnano.6b06414
Alternate JournalACS Nano
PubMed ID28006092