SPR is an optical-electrical phenomenon arising from the interaction of light with a metal surface,
making the detection of the presence of a biopolymer on chemically modified gold surface possible.
The basic principle involved is the change in the local index of refraction upon adsorption of light. The
optical phenomenon is linearly related with the mass concentration adsorbed onto the metal film. The
BIAcore 3000 instrument integrates SPR technology with a microfluidics system to monitor molecular
interactions at real-time molecular interactions at concentrations ranging from pM to mM. The
BIAcore instrument was used in virology applications to detect HIV-1 genomic sequences [108]
demonstrating the possibility to use it in an automated diagnostic system. The SPR technique is a label
free, high throughput and scalable method in array format. It was used by Goodrich and collaborators
to detect multiple DNA targets at a concentration of 10 fM on a single chip [93].