Comparative assessment of the sensitivity of localized surface plasmon resonance transducers and interference-based Fabry-Pérot transducers



Localized surface plasmon resonance (LSPR) transducers have been widely investigated for use in sensing applications. An alternative approach based on interference from thin films (Fabry-Pérot interferometers) has been previously advanced, offering a rather high sensitivity. Both methods involve easily produced substrates and simple optical setups. Here, the sensitivity offered by typical transducers of the two kinds in a usual sensing scenario is compared quantitatively, using experimental and simulated data, and their respective advantages are discussed. To facilitate the comparison a simple sensitivity parameter is proposed. It is concluded that LSPR transducers offer superior sensitivity for analytes and recognition interfaces of small dimensions (up to several nanometers), especially in a wet environment, while the interference transducers become advantageous for thicker layers in dry conditions. For LSPR transducers, significantly higher sensitivity is obtained by using reflection, rather than transmission, measurements.