One common example is a biosensor that measures glucose at the point of analysis. The science behind surface plasmon resonance advanced sharply in 1983 when physical methods for label-free real-time detection of biomolecules started to become possible [1]. Since then, more than two dozen countries have begun to use SPR technology en masse but it is impossible to reliably and accurately track all of the developments realized by those companies. The technology initially was more of a novelty with little to no real-world application but that has changed greatly over the years. One major update to its applications was the Evanescent Wave, which has become an integral and essential concept when discussing SPR sensing [1].

SPR Types

Two of the main types of SPR in place nowadays, those being bulk SPR and localized SPR. Bulk SPR is used to describe SPR that is used with planar surfaces and localized SPR (LSPR) is used for metallic nanoparticles....

The planar surfaces used for bulk SPR have improved greatly over the years. One way this has been done is to use microfluidic flow channels. This allows for usage of reagents that are quite expensive. Thus, these materials can be used more efficiently [2].
Two new SPR types that have come to be as of late are waveguide and fiber SPR sensors. One downside to SPR in the past has been the tendency for mechanical wear to cause the instrument to wear down over time and replacing the glass plate, the oils and such is all quite intensive. This problem can now be circumvented with a singular senor assembly that can be swapped in or out quite easily [2]