Conference proceedings

Immobilization of multi-enzyme microreactors inside microfluidic devices

Koh W, Pishko M ...see all

Sensors and Actuators, B: Chemical, vol. 106, issue 1 SPEC. ISS. (2005) pp. 335-342

  • 46

    Readers

    Mendeley users who have this article in their library.
  • 78

    Citations

    Citations of this article.
  • 3.7k

    Views

    ScienceDirect users who have downloaded this article.
Sign in to save reference

Abstract

A simple method to fabricate enzyme-containing microscopic hydrogel structures in microfluidic devices for the potential use in micro total analysis systems (??-TAS) is described. Poly(ethylene glycol)-based hydrogel microstructures were prepared inside microchannels by photolithography and enzymes conjugated to a pH sensitive fluorophore (SNAFL-1) were incorporated into these hydrogel microstructures. Because of the ratiometric pH-dependent nature of SNAFL fluorescence, hydrogel microstructures exhibited a different emission intensity ratio with pH and this intensity ratio changed almost linearly between pH 7 and 12. When alkaline phosphatase-containing microreactors were exposed to p-nitrophenylphosphate (pNPP) as a substrate, phosphoric acid was produced inside the microstructure by enzymatic-catalyzed hydrolysis of the substrate and subsequently decreased the microenvironment pH. Because of the relatively rapid mass transport of analyte through the hydrogel, enzyme-catalyzed reaction was easily detected by change in emission intensity ratio before and after exposure to substrates. Enzyme-catalyzed reactions were quite fast and reached 90% of maximum value within 10 min. Data were analyzed using a modified Michaelis-Menten equation and apparent Michaelis constants could be obtained. This system was also successfully applied to urea hydrolysis by urease. ?? 2004 Elsevier B.V. All rights reserved.

Author-supplied keywords

  • ??-TAS
  • Enzyme reaction
  • Fluorescence
  • Hydrogel
  • Microfluidic device

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • Won G. Koh

  • Michael Pishko

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free