Enhanced Immobilization of Enzymes on Plasma Micro-Nanotextured Surfaces and Microfluidics: Application to HRP

The enhanced and direct immobilization of the enzyme horseradish peroxidase on poly(methyl methacrylate) (PMMA) microchannel surfaces to create a miniaturized enzymatic reactor for the biocatalytic oxidation of phenols is demonstrated. Enzyme immobilization occurs by physical adsorption after oxygen plasma treatment, which micro-nanotextures the PMMA surfaces. A five-fold enhancement in immobilized enzyme activity was observed, attributed to the increased surface area and, therefore, to a higher quantity of immobilized enzymes compared to an untreated PMMA surface. The enzymatic reaction yield reached 75% using a flow rate of 2.0 μL/min for the reaction mixture. Additionally, the developed microreactor was reused more than 16 times without affecting the enzymatic conversion yield. These results demonstrate the potential of microchannels with plasma micro/nanotextured surfaces for the rapid and facile fabrication of microfluidic enzymatic microreactors with enhanced catalytic activity and stability.