A Multi-Channel SPR Biomolecule Detection System using an Integrated PDMS Nano-Scale Grating Chip

The paper presents a simple multi-channel SPR (surface plasmon resonance) biomolecule detection system using a grating-integrated SPR sensor chip. The present system is composed of a grating-integrated SPR sensor chip for SPR coupling and an external mirror for sequential reflection on each channel in the SPR sensor chip. Compared to the previous multi-channel SPR sensing systems, the present system eliminates bulky and expensive optical components, resulting in the smaller and the simpler system. The SPR sensor chip integrated with nano-scale pitch grating and fluidic channels is fabricated by micromolding technique to reduce the cost of the SPR sensor chip. In the experimental study, the presence of target biomolecule (streptavidin) shifts the SPR dip by 1.0nm; while the SPR dip for reference signal monitoring remains at the same position. From the experimental results, we verify the biomolecule detection performance of the present multi-channel SPR sensing system using a grating- integrated SPR sensor chip.