A new optical label-free biosensing platform based on a metal-insulator-metal structure

A new label-free biosensing platform is proposed based on a metal-insulator-metal (MIM) structure. This platform allows us to perform biosensing by a simple reflectivity measurement at normal incidence illumination without using any bulky optical setup. Theoretical calculation was made to find optimized MIM structural parameters, and experimental results on the label-free biosensing using the MIM platform are presented. This platform has greater sensitivity and mass resolution with respect to the anomalous reflection method, which is a label-free biosensing platform previously proposed by us. Hence, it is suitable for high throughput analysis of biomolecular detection in a microarray format.