Adhesion Study of Escherichia coli Cells on Nano-/Microtextured Surfaces in a Microfluidic System

Control of cell-to-surface adhesion has significant impacts on various biological and biomedical applications. In this study, nano-/microtextured surfaces produced by a unique surface texturing technique, Al-induced crystallization of amorphous silicon, were utilized to control the adhesion of Escherichia coli cells on glass substrates in the fabrication of an E. coli-based whole-cell chemical sensor. Cell adhesion experiments were conducted in microfluidic systems composed of a micromolded polydimethylsiloxane microchannel bonded to a nano-/microtextured glass surface. Cell adhesion on the textured surfaces was monitored and recorded by a phase-contrast microscope equipped with a cooled charge-coupled device camera. It was determined that nano-/microtextured surfaces significantly enhanced cell-to-surface adhesion over microtextured surfaces and smooth surfaces. The number of cells adhered on the nano-/microtextured surfaces was found to be more than two times higher than that on the smooth surfaces for multiple injections of cell culture into the microchannel. Study of the cell-to-surface adhesion mechanism suggests that the number of adhered cells per unit area can be controlled by controlling the particle density on the textured surfaces.