On the application of different bimetallic alloy nanoparticle combinations in fiber optic surface plasmon resonance...

In the present work, we have theoretically investigated the capability of the layer composed of various combinations of bimetallic alloy nanoparticles to be used in fiber optic salinity sensor based on the technique of surface plasmon resonance (SPR). The metals considered for the present analysis are silver, gold, copper, and aluminum. The performance of the sensor with six different bimetallic alloy nanoparticle combinations is evaluated and compared. Furthermore, the performance optimization is carried out in order to minimize the effect of the variation in operating temperature. The overall performance is analyzed in terms of four parameters: sensitivity, signal-to-noise ratio, detection limit, and operating range for the salinity detection in the water sample. On the basis of the comparisons and logistic criteria, the best possible bimetallic alloy combinations along with requisite alloy composition ratio are predicted. The nanoparticle layer made of bimetallic alloy is capable of simultaneously providing larger values of sensitivity, signal-to-noise ratio, detection and operating range, against the temperature-variation compared to single metallic nanoparticle layer.