Department of Chemistry, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC H3C 3J7, Canada.
J Chromatogr A. 2009 Nov 20;1216(47):8270-6. doi: 10.1016/j.chroma.2009.08.069. Epub 2009 Aug 31.
Microencapsulation is used here as a new technique to immobilize enzymes in a microreactor coupled off-line to capillary electrophoresis (CE), allowing the determination of enzymatic reaction products. The redox enzyme laccase was encapsulated using the method of interfacial cross-linking of poly(ethyleneimine) (PEI). The 50 microm diameter capsules were slurry packed from a suspension into a capillary-sized reactor made easily and quickly from a short length of 530 microm diameter fused-silica tubing. The volume of the bed of laccase microcapsules in the microreactor was in the order of 1.1 microL through which 50 microL of the substrate o-phenylenediamine (OPD) was flowed. The oxidation product 2,3-diaminophenazine (DAP) and the remaining OPD were quantified by CE in a pH 2.5 phosphate buffer. Peak migration time reproducibility was in the order of 0.4% RSD and peak area reproducibility was less than 1.7% RSD within the same day. Using the OPD peak area calibration curve, a conversion efficiency of 48% was achieved for a 2-min oxidation reaction in the microreactor.
微胶囊化在这里被用作一种新技术，将酶固定在微反应器中，该微反应器与毛细管电泳（CE）离线耦合，从而可以测定酶反应产物。使用聚（亚乙基亚胺）（PEI）的界面交联方法来包封氧化还原酶漆酶。将 50μm 直径的胶囊从悬浮液中浆状填充到毛细管尺寸的反应器中，该反应器可通过将短的 530μm 直径熔融石英管很容易且快速地制成。微反应器中漆酶微胶囊床的体积约为 1.1μL，其中流过 50μL 的底物邻苯二胺（OPD）。在 pH 2.5 的磷酸盐缓冲液中，通过 CE 对氧化产物 2,3-二氨基吩嗪（DAP）和剩余的 OPD 进行定量。峰迁移时间重现性约为 0.4%RSD，同一天内峰面积重现性小于 1.7%RSD。使用 OPD 峰面积校准曲线，在微反应器中进行 2 分钟的氧化反应，转化率达到 48%。
