No abstract

Detection of bio chemical species in a liquid is very important for research and technical purposes. In the last decade, metallic nanoparticles have been shown to be potential for such measurement. Resonance wavelength (or frequency) of free electron oscillation on metallic nanoparticle surface is very sensitive to tiny changes of its surrounding environment. Change in surrounding medium shifts the resonance wavelength with a slope determined mainly by the size and geometry of nanoparticle. We numerically optimized size and aspect ratio of silver and gold nanoparticles to obtain the highest sensing sensitivity. Here, sensitivity is defined as the slope of resonance wavelength on refractive index of liquid. We found that size, aspect ratio, and material of metal affect sensing sensitivity of metal nanoparticle based sensor significantly.