A Disposable Grating-integrated Multi-channel SPR Sensor Chip for Real-time Monitoring of Biomolecule Binding

The paper presents a multi-channel real-time monitoring of biomolecule binding using a disposable SPR (Surface Plasmon Resonance) sensor chip integrated with nano-scale pitch grating. The sensor chip has two fluidic channels for sample delivery and gratings in each fluidic channel for SPR sensing. An external mirror makes an incidence of light at different angles on each sensing channel, thus generating two SPR dip at different spectral band. The gratings on the SPR sensor chip are fabricated by micromolding process for disposable application. We monitor the biotin-streptavidin binding reaction in real-time. The binding reaction using 0.2 muM streptavidin solution on the biotinylated surface is saturated in 30 min. The refractive index sensitivity of the SPR sensor chip is also characterized as 321.78 nm/RI at the sensing wavelength of 607 nm and 512.26 nm/RI at 704 nm.