Increase of reaction rate and sensitivity of low-abundance enzyme assay using micro/nanofluidic preconcentration chip

Jeong Hoon Lee, Yong Ak Song, Steven R. Tannenbaum, Jongyoon Han

Research output: Contribution to journalArticle

Abstract

We report a novel method of increasing both the reaction rate and the sensitivity of low-abundance enzyme assay using a micro/nanofluidic preconcentration chip. The disposable preconcentration device made out of PDMS with a surface-patterned ion-selective membrane increases local enzyme/substrate concentrations for rapid monitoring of enzyme activity. As a model system, we used trypsin as the enzyme and BODIPY FL casein as the fluorogenic substrate. We demonstrated that the reaction rate of trypsin-BODIPY FL was significantly enhanced by increasing the local concentrations of both trypsin and BODIPY FL casein in the preconcentration chip. The reaction time required to turn over substrates at 1 ng/mL was only ∼10 min compared to ∼1 h without preconcentration, which demonstrates a significantly higher reaction rate through the increase of the concentrations of both the enzyme and substrate. Furthermore, trypsin activity can be measured down to a concentration level of 10 pg/mL, which is a ∼100 fold enhancement in sensitivity compared to the result without the preconcentration step. This micro/nanofluidic preconcentrator chip could be used as a generic micro reaction platform to study any enzyme-substrate systems, or other biochemical reaction systems in low concentration ranges.

Original languageEnglish (US)
Pages (from-to)3198-3204
Number of pages7
JournalAnalytical chemistry
Volume80
Issue number9
DOIs
StatePublished - May 1 2008

ASJC Scopus subject areas

  • Analytical Chemistry

Fingerprint Dive into the research topics of 'Increase of reaction rate and sensitivity of low-abundance enzyme assay using micro/nanofluidic preconcentration chip'. Together they form a unique fingerprint.

  • Cite this