Study the Optical Properties of Noble Metal (Au, Ag, and Cu) Thin Film Biosensors Based on Surface Plasmon Resonance Performance by a Simulation Program

Abstract

In this work, we studied the effect noble metal thicknesses, namely gold (Au), silver (Ag), and copper (Cu) on the surface plasmon resonance (SPR) characteristics for sensitive optical sensor and biosensor applications. SPR spectra for Au, Ag and Cu were widely studied in the Fresnel equation to calculate the total reflection, the wavelength ([Formula: see text] range from 500 nm to 700 nm with the angle of incidence ([Formula: see text] ranging from 0[Formula: see text] to 90[Formula: see text] and thickness of the film ([Formula: see text] reaching from 30 nm to 70 nm. Analysis simulation (in MATLAB) has been made for SPR of three metals placed on the N_LASF9 glass prism and the sensing medium is the air. The properties of the angle of resonance [Formula: see text] have been calculated from plotted reflectance via incident angle [Formula: see text]. The results give efficient detection in a change of reflection ([Formula: see text] and full half width maximum FWHM. The minimum reflection was obtained (0.003 a.u.) at wavelength 700 nm and thickness [Formula: see text]= 50 nm for gold Au at [Formula: see text] = 0.0. The best FWHM was recorded at the wavelength (500 nm) at thickness (70 nm) for silver at [Formula: see text] = 0.0, which was equal (0.1 nm).