Authors: R. Naidoo, A. Singh, N. Glass, S. Arya, S. Evoy
Affilation: National Institute for Nanotechnology, University of Alberta, Canada
Pages: 456 - 458
Keywords: wild-type bacteriophage, size-exclusion chromatography, bacterial biosensor
We report in this study the largest surface capture density of E Coli using the wild-type T4 bacteriophage; whereby higher surface capture density can enable higher sensitivities for surface-based biosensors. This was possible due to our purification of the phage lysate by size-exclusion chromatography, which significantly improved phage surface density, achieving maximum (jamming) surface coverage. Additionally we purified two other bacteriophages: P22 and Campy P1, and also show that their phage surface densities improved greatly relative to unpurified suspensions. One would expect that by attaining the jamming coverage of phages on the surface that this would correlate with the highest possible bacterial capture density – however it is not the case. We have instead determined an optimal phage surface density for the model T4 system. This could be due to the excessive phage aggregation observed in SEM micrographs at higher surface densities. Our work reveals that phage attachment to the surface does not obey the idealized Langmuir isotherm, but the newly elucidated Brouers-Sotolongo isotherm - suggesting a highly heterogeneous surface. Therefore, phages that initially attach to the surface could be providing lower-energy sites for additional phage attachment, causing the observed aggregation on the surface.