[...]... technique to detect changes in the local refractive index near the surface of a thin metal (typically gold) film (2) Avraham Rasooly and Keith E Herold (eds.), Methods in Molecular Biology: Biosensors and Biodetection, Vol 503 © Humana Press, a part of Springer Science + Business Media, LLC 2009 DOI: 10.1007/978-1-60327-567-5_1 3 4 Arima et al Figure 1 shows an SPR apparatus of Kretchmann configuration... amplification circuit, the detection precision is degraded, commonly no better than 10−6 refractive index unit (RIU) Avraham Rasooly and Keith E Herold (eds.), Methods in Molecular Biology: Biosensors and Biodetection, Vol 503 © Humana Press, a part of Springer Science + Business Media, LLC 2009 DOI: 10.1007/978-1-60327-567-5_2 21 22 Ding, Liu, and Yu In proteomics research and drug discovery, the voice .