
76 Biosensors Based on Nanomaterials and Nanodevices
(or nonuorescent) organic dye as the energy acceptor. In the classical FRET process, the
efcient energy transfer distance ranges from 3 to 8 nm, which is typically the size of
a protein or the thickness of a cellular membrane. Nevertheless, the limited detectable
distance cannot meet the requirements in case the extending detectable distance is being
sought in the resonance energy transfer–based applications. Recently, Au nanoparticles
(NPs) and graphene oxide (GO) have emerged as alternatives to the organic dye molecules
in the energy transfer systems [18–22]. These novel quenchers circu ...