Waveguide coupled surface plasmon resonance imaging measurement and high-throughput analysis of bio-interaction

A novel surface plasmon resonance imaging (SPRi) biosensor based on waveguide coupled surface plasmon resonance (WCSPR) measurements is reported. Simply fabricated by gold evaporation deposition and polymer spin-coating, the WCSPR chips can be easily adapted on an commercial SPRi monitoring instrument. The chips were designed by using Fresnel method and fabricated according to its optimized design, the calculation and experimental results fits well. Over an 8 mm × 8 mm rectangle imaging area, the WCSPR chips realized about 52% increase of sensitivity, 57% enhancement of resolution and 55% improvement of signal to noise ratio compared to conventional SPR chips. Furthermore, high throughput protein–protein interaction analyses based on WCSPR chips were successfully accomplished by applying Protein A and rabbit antibody interaction in an array format. The reflectivity responses observed from the WCSPR chips were about 50% higher than the conventional SPR chip while the binding kinetic parameters were within the same range as with conventional SPR chip.