Application of periodic gold nanohole arrays fabricated by interference lithography technique as SERS probes for chemical species

Luis E. G. Armas¹, Jacson W. Menezes¹, Manuel F. G. Huila², Koiti Araki², Henrique E. Toma², Lizandro B. R. Zegarra³

¹ Univsersidade Federal do Pampa-Campus Alegrete, CP 9756-550, Rio Grande do Sul, RS, Alegrete, Brazil

² Instituto de Química da Universidade de São Paulo – USP, CP 26077, São Paulo, SP, Brazil

³ Departamento de Matemática de la Universidad Nacional del Santa-UNS, Chimbote, Perú 

Periodic array of Nanoholes (PANhs) in gold films have been shown to be more transparent at certain wavelengths than expected by the classical aperture theory [1]. This extradordinary optical transmisión (EOT) has been atributted mainly to surface plasmons excitations that mediate the light transmission from one side of the film to the other under resonance conditions [2,3]. The Interference Lithography (IL) technique is based on the interference of coherent radiation in the visble range [4]. In the present study, we report the application of PANhs fabricated by IL technique as SERS probes of chemical species, such as Rhodamine 6G (Rh6G) and 4-4^’ Bipyridine (Bipy) molecules. It was observed and enhancement of the main bands of Rh6G and Bypi molecules, when deposited on the surface of PANhs, in comparison that when deposited on the surface of 5 nm flat gold film. Our study indicates that metallic nanostrcutures fabricated by IL technique have the potential for high impact on biochemical sensing, such as DNA and bacterial detection, real time glucose sensing for diabetes, and in situ identification of reaction products.

Keywords: interference lithography, SERS, Nanoholes, Rhodamine 6G, Raman Spectroscopy