Bat Erhan, Lin En-Wei, Saxer Sina, Maynard Heather D
Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California, 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California, 90095, USA.
Macromol Rapid Commun. 2014 Jul;35(14):1260-5. doi: 10.1002/marc.201400160. Epub 2014 Apr 17.
Stimuli responsive surfaces that show reversible fluorescence switching behavior in response to temperature changes were fabricated. Oligo(ethylene glycol) methacrylate thermoresponsive polymers with amine end-groups were prepared by atom transfer radical polymerization (ATRP). The polymers were patterned on silicon surfaces by electron beam (e-beam) lithography, followed by conjugation of self-quenching fluorophores. Fluorophore conjugated hydrogel thin films were bright when the gels were swollen; upon temperature-induced collapse of the gels, self-quenching of the fluorophores led to significant attenuation of fluorescence. Importantly, the fluorescence was regained when the temperature was cooled. The fluorescence switching behavior of the hydrogels for up to ten cycles was investigated and the swelling-collapse was verified by atomic force microscopy. Morphing surfaces that change shape several times upon increase in temperature were obtained by patterning multiple stimuli responsive polymers.
制备了对温度变化呈现可逆荧光开关行为的刺激响应表面。通过原子转移自由基聚合（ATRP）制备了具有胺端基的聚乙二醇甲基丙烯酸酯热响应聚合物。通过电子束光刻将聚合物图案化在硅表面上，随后连接自猝灭荧光团。当凝胶溶胀时，荧光团共轭水凝胶薄膜是明亮的；随着温度诱导凝胶塌陷，荧光团的自猝灭导致荧光显著衰减。重要的是，当温度冷却时荧光恢复。研究了水凝胶长达十个循环的荧光开关行为，并通过原子力显微镜验证了溶胀-塌陷情况。通过图案化多种刺激响应聚合物获得了在温度升高时形状多次变化的变形表面。
