Hydrogel-Terminated Photonic Crystal for Label-Free Detection of Angiopoietin-1

We report on a label-free time-resolved biosensing technique based on refractometric measurements. A one-dimensional photonic crystal (1-DPC) constituted by a planar stack of dielectric layers is used for supporting Bloch surface waves. These electromagnetic surface waves probe the aqueous environment within few hundreds of nanometers from the photonic crystal surface, which is functionalized with a hydrogel binding matrix. Therein, selected antibodies are grafted for the specific recognition of the tumoral biomarker Angiopoietin-1. A model bioassay is established demonstrating a detection of Antiopoiegin-1 as low as picomolar concentrations.