radiative and non-radiative surface plasmon resonance: comparison of real-time sensing performance

The work presents a surface plasmon resonance sensor able to operate the non-radiative and radiative surface plasmons simultaneously. the optical coupling between photons and surface plasmons was mediated by a rough surface, allowing the photon emission by radiative plasmons excitation process. experimental tests with reversible and irreversible binding were performed, and the results were compared. the spr curve profile indicates normalized values < 1 for sp absorption and values > 1 for sp emission. this feature suggests the involvement of localized sp-states that co-exist in the film with delocalized propagating sp state. the data extraction process and the performance of these two excitation forms are also reported. the higher performance of the non-radiative surface plasmons absorption is by a factor of 4.