Sensitivity analysis of a label-free detection using Opto-plasmonic nano-structured antenna

This paper reports a design method of optoplasmonics sensor that consider a pair of elliptical gold nano antenna mounted on a quartz substrate. A 2D array of gold nano antenna can be used for a variety of biomedical applications due to its key electronic and optical properties which are shape and size dependent. An elliptical shaped coupled gold nano antenna with 100 nm major axis, a and 10 nm minor axis, b was optimized with separation distance, g and height, h to achieve a high sensitivity with a narrow full-width half-maximum (FWHM) and a good figure of merit (FOM). By exploiting the resonance shift of transmission spectra and high electric field confinements, the sensitivity of the proposed sensor was obtained nearly 526-530 nm/RIU and the FWHM and FOM were calculated around 110 nm and 8.1, respectively. Additionally, the proposed sensing structure have been explored to measure the 2-propanol (IPA) concentration in water.