Sensitive, label-free protein assay using 1-ethyl-3-methylimidazolium tetrafluoroborate-supported microchip electrophoresis with laser-induced fluorescence detection.

Journal Article (Journal Article)

Based on the dimer-monomer equilibrium movement of the fluorescent dye Pyronin Y (PY), a rapid, simple, highly sensitive, label-free method for protein detection was developed by microchip electrophoresis with LIF detection. PY formed a nonfluorescent dimer induced by the premicellar aggregation of an anionic surfactant, SDS, however, the fluorescence intensity of the system increased dramatically when proteins such as BSA, bovine hemoglobin, cytochrome c, and trypsin were added to the solution due to the transition of dimer to fluorescent monomer. Furthermore, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) instead of PBS was applied as running buffers in microchip electrophoresis. Due to the excellent properties of EMImBF4, not only nonspecific protein adsorption was more efficiently suppressed, but also approximately ten-fold higher fluorescence intensity enhancement was obtained than that using PBS. Under the optimal conditions, detection limits for BSA, bovine hemoglobin, cytochrome c, and trypsin were 1.00x10(-6), 2x10(-6), 7x10(-7), and 5x10(-7) mg/mL, respectively. Thus, without covalent modification of the protein, a protein assay method with high sensitivity was achieved on microchips.

Full Text

Duke Authors

Cited Authors

  • Xu, Y; Li, J; Wang, E

Published Date

  • May 2008

Published In

Volume / Issue

  • 29 / 9

Start / End Page

  • 1852 - 1858

PubMed ID

  • 18393338

International Standard Serial Number (ISSN)

  • 0173-0835

Digital Object Identifier (DOI)

  • 10.1002/elps.200700499


  • eng

Conference Location

  • Germany