L.D. Mauludi, R.A. Firdaus, M. Yantidewi, W.P. Tresna, A. Khumaeni
This study has investigated SPR sensors using plasmonic bimetal, varying the combination of Au-Ag thickness to obtain good sensitivity. In this case, heavy metal analytes are used to test the sensitivity obtained. Simulation and analysis methods were carried out in depth to test the configuration capabilities of each plasmonic bimetal. Although the single Au configuration showed better stability, the Ag characteristics outperformed it in terms of sensitivity. Thus, to obtain optimum sensitivity, the thickness of each plasmonic bimetal was varied with a total thickness remaining at 50 nm. The analysis results show that at thickness variations of 10Au-40Ag nm, the minimum transmittance (Tspr) is almost zero. Meanwhile, the thickness variations of 20Au-30Ag nm, 25Au-25Ag nm and 40Au-10Ag nm still have Tspr values in the range of 0.2-0.4 nm. Other analysis results show that the thicker the Ag material in the bimetal combination, the narrower the FWHM value of the resulting deep resonance spectrum tends to be. In the variations of heavy metal analytes used such as Cu, Pb, Hg, Zn, Fe and Co, the sensor quality parameters did not show the same trend for each analyte. Overall, the research methodology conducted shows that plasmonic bimetal variations can improve sensor quality parameters for several heavy metal analytes. © 2025, National Institute of Optoelectronics. All rights reserved.
Departement of physics, State University of Surabaya (UNESA), Surabaya, Indonesia; National Research and Innovation Agency (BRIN), Tangerang Selatan, Indonesia; Departement of physics, Diponegoro University, Semarang, Indonesia
