Department of Chemistry , The Chinese University of Hong Kong , Shatin , N.T., Hong Kong , P. R. China.
The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi 214122 , P. R. China.
ACS Appl Mater Interfaces. 2020 Jan 29;12(4):4989-4997. doi: 10.1021/acsami.9b16117. Epub 2020 Jan 17.
Water-in-oil (w/o) Pickering emulsions have received considerable attention in biphasic enzymatic catalysis for their advantages of good stability, large interfacial area, and ease of product separation. However, enzymes are commonly encapsulated in the interior of aqueous droplets, which inevitably increases the diffusional resistance to catalysis. Alternatively, enzymes are immobilized or trapped into Pickering stabilizers. Often, however, these approaches suffer from leaching and a decrease of enzyme activity during the chemical treatments. We report here a new Pickering interfacial biocatalysis platform with efficient enzyme encapsulation, binary particle composition, and high catalytic performance. Our approach is based on w/o Pickering emulsions stabilized by binary particles consisting of hard silica and soft, pH-responsive microgel particles. We demonstrate that pH-responsive microgels can simultaneously stabilize a w/o Pickering emulsion, encapsulate enzymes, and catalyze reactions at the water/oil interface. In addition, we show that the coordination with rigid silica nanoparticles as additional stabilizers markedly improves the emulsion structure and will provide a new avenue for the preparation of w/o Pickering emulsion and concept of biphasic catalysis.
油包水（w/o）Pickering 乳液因其良好的稳定性、较大的界面面积和易于产物分离等优点，在两相酶催化中受到了相当多的关注。然而，酶通常被包裹在水相液滴的内部，这不可避免地增加了催化的扩散阻力。或者，酶被固定或捕获到 Pickering 稳定剂中。然而，这些方法通常会在化学处理过程中发生浸出和酶活性下降。我们在这里报道了一种具有高效酶封装、二元颗粒组成和高催化性能的新型 Pickering 界面生物催化平台。我们的方法基于由硬二氧化硅和软、pH 响应微凝胶颗粒组成的二元颗粒稳定的 w/o Pickering 乳液。我们证明，pH 响应微凝胶可以同时稳定 w/o Pickering 乳液、封装酶，并在油水界面催化反应。此外，我们还表明，与刚性二氧化硅纳米粒子的协同作用作为额外的稳定剂显著改善了乳液结构，并将为 w/o Pickering 乳液的制备和两相催化概念提供新的途径。
