Enhancement of the sensitivity of surface plasmon resonance biosensor with colloidal gold labeling technique

In our experiment colloidal gold was used to enhance the signal obtained from the surface-plasmonresonance biosensor. Fab′ fragments of human IgG molecules were immobilized on the gold surface and reacted with the sheep-anti-human IgG(SAH-IgG) molecules in solution. It was found that when the colloidal gold labeling technique was introduced the sensitivity of surface plasmon resonance instruments increased by a factor of about 300.