Bimetallic auag nanostructured photonic Chip via excimer laser irradiation and external electric field for LSPR optical sensing and enhanced Raman scattering

This paper presents the fabrication of photonic chips incorporating gold‑silver (Au Ag) bimetallic nanoparticles via a laser-induced method. Thin films of Au Ag were deposited on polycarbonate substrates and subsequently irradiated with an ArF excimer laser. During laser exposure, an external electric field of 10 5 V/m was applied to study its influence on nanostructure formation. The morphological development and properties of the resulting nanostructures were investigated under both the presence and absence of the electric field. The results show that the diameters of the fabricated nanostructures in both conditions predominantly ranged from 40 to 100 nm. Notably, the application of the external electric field promoted the formation of larger linear clusters compared to samples formed without applying the electric field. Raman spectroscopy of a 10 −4 M Rhodamine B solution revealed that the Au Ag nanoparticles fabricated without the external electric field exhibited strong surface-enhanced raman scattering (SERS) activity. Furthermore, LSPR optical sensing tests confirmed the suitability of both samples, with sensitivities of 933.5 nm/RIU and 663.1 nm/RIU for nanostructures produced without and with the external electric field, respectively.