Fig. 6.

Operation of a surface plasmon resonance biosensor. (a) The glass of the sensor chip is coated with a thin layer of gold, a dextran matrix is attached via a linker layer to the gold and receptors are cross-linked to the dextran. Light is reflected from the surface of a sensor chip and resonant absorption is seen at an angle dependent on the quantity of material bound at the surface. (b) When an interaction occurs, a shift in the resonant angle is observed that is proportional to the amount of material bound. A plot of resonance signal vs. time, the sensogram, can be monitored in real time