Title | Simultaneous Measurement of the Dissolution Kinetics of Responsive DNA Hydrogels at Multiple Length Scales. |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | Simon AJ, Walls-Smith LT, Freddi MJ, Fong FYi, Gubala V, Plaxco KW |
Journal | ACS Nano |
Volume | 11 |
Issue | 1 |
Pagination | 461-468 |
Date Published | 2017 Jan 24 |
ISSN | 1936-086X |
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. |
DOI | 10.1021/acsnano.6b06414 |
Alternate Journal | ACS Nano |
PubMed ID | 28006092 |