title: Real-time biomolecular binding detection using a sensitive photonic crystal biosensor.
abstract: Real-time measurement of specific biomolecular interactions is critical to many areas of biological research. A number of label-free techniques for directly monitoring biomolecular binding have been developed, but it is still challenging to measure the binding kinetics of very small molecules, to detect low concentrations of analyte molecules, or to detect low affinity interactions. In this study, we report the development of a highly sensitive photonic crystal biosensor for label-free, real-time biomolecular binding analysis. We characterize the performance of this biosensor using a standard streptavidin-biotin binding system. Optimization of the surface functionalization methods for streptavidin immobilization on the silica sensing surface is presented, and the specific binding of biotinylated analyte molecules ranging over 3 orders of magnitude in molecular weight, including very small molecules (<250 Da), DNA oligonucleotides, proteins, and antibodies (>150 000 Da), are detected in real time with a high signal-to-noise ratio. Finally, we document the sensor efficiency for low mass adsorption, as well as multilayered molecular interactions. By all important metrics for sensitivity, we anticipate this photonic crystal biosensor will provide new capabilities for highly sensitive measurements of biomolecular binding.
authors.affiliation: Center for Ultrafast Optical Science, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, USA. guoybyw@umich.edu
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Guo
authors.forename: Jing Yong
authors.initials: JY
authors.lastname: Ye
authors.forename: Charles
authors.initials: C
authors.lastname: Divin
authors.forename: Baohua
authors.initials: B
authors.lastname: Huang
authors.forename: Thommey P
authors.initials: TP
authors.lastname: Thomas
authors.forename: James R
authors.initials: JR
authors.lastname: Baker
authors.forename: Theodore B
authors.initials: TB
authors.lastname: Norris
mesh_terms: D000906:Antibodies / Q000378:metabolism; D001665:Binding Sites; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000378:metabolism*; D019921:Biotinylation; D009841:Oligonucleotides / Q000378:metabolism; D017785:Photons; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism; D012680:Sensitivity and Specificity; D019809:Streptavidin / Q000378:metabolism*
chemical_list: D000906:Antibodies; D009841:Oligonucleotides; D011506:Proteins; D001710:Biotin; D019809:Streptavidin