title: Development of an enzymatic microreactor based on microencapsulated laccase with off-line capillary electrophoresis for measurement of oxidation reactions.
abstract: 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.
authors.affiliation: Department of Chemistry, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC H3C 3J7, Canada.
authors.forename: Georgiana
authors.initials: G
authors.lastname: Roman-Gusetu
authors.forename: Karen C
authors.initials: KC
authors.lastname: Waldron
authors.forename: Dominic
authors.initials: D
authors.lastname: Rochefort
mesh_terms: D019149:Bioreactors; D002138:Calibration; D004339:Drug Compounding; D019075:Electrophoresis, Capillary / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D042845:Laccase / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D010619:Phenazines / Q000737:chemistry / Q000378:metabolism; D010655:Phenylenediamines / Q000737:chemistry / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D004800:Enzymes, Immobilized; D010619:Phenazines; D010655:Phenylenediamines; C054312:2,3-diaminophenazine; C034193:1,2-diaminobenzene; D042845:Laccase