Synthesis and functionalization of poly(ethylene glycol) microparticles as soft colloidal probes for adhesion energy measurements
Synthesis and functionalization of poly(ethylene glycol) microparticles as soft colloidal probes for adhesion energy measurements
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DOI：
10.1039/c2sm06911c
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发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Hartmann, Laura
中科院分区：
文献类型：
--
作者：
Pussak, Daniel;Behra, Muriel;Hartmann, Laura
本文报道了新型软胶体探针(SCP)的合成和操作，作为粘附能测量的传感器。测量包括使用Johnson-Kendall-Roberts(JKR)方法确定粘着的热力学功。为了最大限度地提高水介质中粘附力测量的灵敏度和特异度，我们使用了高顺应性的聚乙二醇微粒子作为SCP。聚乙二醇的化学惰性提供了作为探针材料的优势，但同时也使官能团的整合变得复杂。因此，我们专注于开发一种直接但可变的表面修饰过程，涉及到使用二苯甲酮作为光引发剂的自由基表面化学。通过这种高度通用的方法，我们能够将各种官能团，如羧基或胺基直接引入到聚乙二醇网络中。然后，这些功能化的SCP可以用更复杂的结构进一步修饰，如树枝状低聚物(氨基胺)。利用第一组SCP，测量了模型表面的附着能，揭示了水中酸碱、静电和疏水相互作用的贡献。我们成功地证明，开发的聚乙二醇类探针可以在不需要昂贵仪器的情况下研究接触行为，并且具有高灵敏度，适合于检测非常弱的(生物)相互作用。
We report on the synthesis and operation of new soft colloidal probes (SCPs) as sensors for adhesion energy measurements. The measurements involve determination of the thermodynamic work of adhesion using the Johnson-Kendall-Roberts (JKR) approach. To maximize the sensitivity as well as the specificity of adhesion measurements in aqueous media we use highly compliant poly(ethylene glycol) (PEG) microparticles as SCPs. The chemical inertness of PEG offers advantages as probe material, but at the same time complicates the integration of functional groups. Consequently, we focus on the development of a straightforward yet variable surface modification procedure involving radical surface chemistry using benzophenone as the photoinitiator. With this highly versatile method we are able to introduce various functionalities like carboxy or amine groups directly to the PEG network. These functionalized SCPs can then be further modified with more complex structures such as dendritic oligo(amidoamines). With a first set of SCPs, adhesion energies were measured on model surfaces revealing the contributions due to acid-base, electrostatic and hydrophobic interactions in water. We successfully showed that the developed PEG probes allow for the study of contact behaviour without expensive instrumentation and with high sensitivity suitable to detect very weak (biological) interactions.