Gi Hun Seong

This paper describes a microanalytical method for determining enzyme kinetics using a continuous-flow microfluidic system. The analysis is carried out by immobilizing the enzyme on microbeads, packing the microbeads into a chip-based microreactor (volume approximately 1.0 nL), and flowing the substrate over the packed bed. Data were analyzed using the Lilly-Hornby equation and compared to values obtained from conventional measurements based on the Michaelis-Menten equation. The two different enz

A strategy for efficiently mixing solutions and carrying out multistep catalytic reactions in microfluidic systems is described. The approach involves immobilizing catalysts on microbeads, placing the beads into well-defined microreactor zones, and then passing reactants through one or more of the reactor zones to yield products. The catalyst-modified beads effectively mix reactants and increase the effective surface area of the channel interior, both of which improve reaction velocities compare

This paper describes fabrication of serial microchamber arrays within the channels of a microfluidic device. The chambers are defined using a combination of weirs and UV-cross-linked hydrogel plugs (poly(ethylene glycol) diacrylates). This approach permits the microchambers to be addressed by pump-driven pressure in one dimension and by electrophoresis in the other. The function of the device is demonstrated by detecting DNA targets. Single-strand DNA (ssDNA) probes labeled with biotin were immo

We controlled the morphologies of zinc oxide (ZnO) nanostructures on single-walled carbon nanotube electrodes by an electrochemical deposition method and investigated the dependence of the electrocatalytic characteristics toward hydrazine on the different morphologies. ZnO nanorods provided high electrocatalytic activity with unique electrochemical behaviours, associated with the H(+) ion generated by the electro-oxidation of hydrazine.