Probing polymerization dynamics with fluorescent molecular rotors and magnetoelastic sensors
Probing polymerization dynamics with fluorescent molecular rotors and magnetoelastic sensors
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DOI：
10.1166/sl.2006.031
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发表时间：
2006-09-01
期刊：
影响因子：
--
通讯作者：
Grimes, Craig A.
中科院分区：
文献类型：
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作者：
Haidekker, Mark A.;Lichlyter, Darcy;Grimes, Craig A.
我们比较了两种不同的传感器探测三种流行的生物聚合物的聚合动力学的能力：聚丙烯酰胺，型胶原蛋白，和基于四甲氧基硅烷的溶胶-凝胶。传感器是（1）非晶金属-玻璃材料的磁致弹性（ME）条，其在射频磁场中激发后执行粘度依赖性阻尼振荡，以及（2）具有粘度依赖性量子产率的荧光分子转子。在引发聚合反应后，记录ME条带的共振品质因子Q和暴露于聚合物的分子转子的发射强度。在聚丙烯酰胺中，ME条带的Q因子以指数方式下降，反映了逐渐交联单体的刚性增加。分子转子被自由基供体过硫酸铵淬灭。在胶原凝胶中，增加交联伴随着分子转子发射强度的显着增加。相比之下，ME条显示Q仅轻微降低。溶胶-凝胶聚合伴随着ME条的Q的降低。分子转子强度表现出更复杂的模式，其中可以区分水解和聚合阶段。总之，ME条和分子转子都允许实时监测聚合过程。因此，胶原凝胶化过程和最终硬度的荧光探测是可行的。最后，这两个传感器显示出强烈的反应，在溶胶-凝胶，但也出现提供信息的动态胶凝过程中，即水解和交联阶段。
We compared the ability of two different sensors to probe the polymerization dynamics of three popular biopolymers: Polyacrylamide, typed collagen, and tetramethoxysilane-based sol-gel. The sensors were (1) a magnetoelastic (ME) strip of amorphous metal-glass material performing a viscosity-dependent dampened oscillation after excitation in a radiofrequency magnetic field, and (2) a fluorescent molecular rotor with a viscosity-dependent quantum yield. Both the resonance quality factor Q of the ME strip and the emission intensity of the molecular rotor, exposed to the polymers, were recorded after initiating the polymerization reaction. In polyacrylamide, the Q factor of the ME strip decreased in an exponential fashion, reflecting increased rigidity of the progressively crosslinking monomers. The molecular rotor was quenched by the free-radical donor ammonium persulfate. In collagen gels, increasing crosslinking was accompanied by a marked increase of molecular rotor emission intensity. In contrast, the ME strip showed only a minor decrease in Q. Sol-gel polymerization was accompanied by a decrease of Q of the ME strip. Molecular rotor intensity exhibited a more complex pattern, where hydrolysis and polymerization phases could be distinguished. In conclusion, both the ME strip and the molecular rotors allow monitoring of polymerization processes in real-time. Fluorescent probing of the collagen gelation process and final rigidity is therefore feasible. Finally, both sensors showed a strong reaction in sol-gels, but also appeared to provide information on the dynamics of the gelation process, namely the hydrolysis and crosslinking phase.