Kinetics of Enzymatic Reactions at the Solid/Liquid Interface in Nanofluidic Channels

Nanostructures can realize highly efficient reactions due to their structural advantages. However, the mechanism of accelerating enzyme reactions in a nanospace is still unknown from a kinetic perspective because it is difficult to control a well-defined nanospace, enzyme density, and reaction time. Here, we investigated kinetic parameters of an immobilized enzyme in micro- and nanochannels using nanofabrication, partial enzyme patterning, fluidic control, and a high sensitivity detection system. Devices with channel depths of 300 nm, 4.4 mu m, and 13.6 mu m were fabricated. Kinetic parameters were determined by the Michaelis-Menten model. Compared to the bulk reaction, all k(cat)s for immobilized enzyme reactors were decreased, although the k(cat)s were approximately the same for the immobilized enzyme reactors of different depths. An ultrafast enzyme reaction could overcome the drawback due to immobilization by an increase of the apparent [E](0) due to the decreased channel depth.

Automated summary

Nanostructures can achieve highly efficient reactions, but the mechanism of accelerating enzyme reactions in a nanospace is still unknown. This study investigated the kinetic parameters of immobilized enzymes in micro- and nanochannels using nanofabrication, partial enzyme patterning, fluidic control, and a high sensitivity detection system.