Effect of gold nanoparticles and unwanted residues on raman spectra of graphene sheets - Gomez Armas, Luis Enrique; Zamarion, Vitor de Moraes; Quispe, Luis T; Otero, Enrique P. U; Menezes, J. W; Zegarra, Lizandro B. R; Rahim, Abdur; Araki, Koiti; Toma, Henrique Eisi; Jacinto, Carlos; Valsechi, Chiara; Seabra, Antonio Carlos (Brazilian Journal of Physics, 2018)