Exploring the temperature-dependent kinetics and thermodynamics of immobilized glucose oxidase in microchip

Abstract

Herein, we report a method to investigate the thermodynamics and kinetics of immobilized enzyme (Glucose Oxidase, GOD) catalytic reaction on a microfluidics platform with precise temperature-control using a home-made plexiglass temperature controllable holder. This approach allows us to extract kinetic and thermodynamic parameters of the immobilized enzyme catalytic reactions easily, showing significant advantages over the traditional calorimetric and microcalorimetric methods which require complex fabrication of thermally isolated system. In our approach, the Arrhenius equation is introduced to establish the relationship between the kinetics and thermodynamics of the immobilized GOD. Results show that the obtained activation energy (Ea = 60.56 kJ mol−1) and the activation enthalpy (ΔHa = 53.08 kJ mol−1) are smaller than free enzymes, demonstrating that the immobilized GOD exhibits improved thermal stability compared with free enzymes. The present work offers an alternative approach to achieve the kinetics and thermodynamics of immobilized enzyme catalytic reactions on a microfluidics chip and promote our understanding of enzyme catalytic reactions.