title: Planar Photonic Crystal Biosensor for Quantitative Label-Free Cell Attachment Microscopy.
abstract: In this study, a planar-surface photonic crystal (PC) biosensor for quantitative, kinetic, label-free imaging of cell-surface interactions is demonstrated. The planar biosensor surface eliminates external stimuli to the cells caused by substrate topography to more accurately reflect smooth surface environment encountered by many cell types in vitro. Here, a fabrication approach that combines nanoreplica molding and a horizontal dipping process is used to planarize the surface of the PC biosensor. The planar PC biosensor maintains a high detection sensitivity that enables the monitoring of live cell-substrate interactions with spatial resolution sufficient for observing intracellular attachment strength gradients and the extensions of filopodia from the cell body. The evolution of cell morphology during the attachment and spreading process of 3T3 fibroblast cells is compared between planar and grating-structured PC biosensors. The planar surface effectively eliminates the directionally biased cellular attachment behaviors that are observed on the grating-structured surface. This work represents an important step forward in the development of label-free techniques for observing cellular processes without unintended external environmental modulation.
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Weili
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Long
authors.affiliation: Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Jonas
authors.initials: J
authors.lastname: Kurniawan
authors.affiliation: School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Margaret
authors.initials: M
authors.lastname: Hung
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Hojeong
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Brendan A
authors.initials: BA
authors.lastname: Harley
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Cunningham