In this work we report on an active SERS (Surface Enhanced Raman Scattering) substrate with well-defined silver microholes for the investigation of liquid samples. The femtoliter volume confined in the holes allows to perform analysis of non-transparent aqueous solutions reducing fluorescence emission and avoiding signal absorption by surrounding liquid, which was demonstrated in the case of opaque and dye solutions. The micro-pattern based substrate was obtained by optical lithography and reactive ion etching and was selectively covered with silver nanoislands arranged in a highly homogeneous and isotropic way. Dopamine molecules and cell culture medium were used as probe analytes for SERS experiments showing that plasmonic microholes, having a very uniform enhancement, are suitable both for the detection of molecules with low Raman cross section and for the detection of biomolecules of non-transparent complex solutions. Finally, this kind of analysis requires only a tiny amount of analyte which is an important advancement for the measurements of costly or precious samples.
Plasmonic microholes for SERS study of biomolecules in liquid
La Rocca R.;Perrone M.;Gentile F.;De Angelis F.
2016-01-01
Abstract
In this work we report on an active SERS (Surface Enhanced Raman Scattering) substrate with well-defined silver microholes for the investigation of liquid samples. The femtoliter volume confined in the holes allows to perform analysis of non-transparent aqueous solutions reducing fluorescence emission and avoiding signal absorption by surrounding liquid, which was demonstrated in the case of opaque and dye solutions. The micro-pattern based substrate was obtained by optical lithography and reactive ion etching and was selectively covered with silver nanoislands arranged in a highly homogeneous and isotropic way. Dopamine molecules and cell culture medium were used as probe analytes for SERS experiments showing that plasmonic microholes, having a very uniform enhancement, are suitable both for the detection of molecules with low Raman cross section and for the detection of biomolecules of non-transparent complex solutions. Finally, this kind of analysis requires only a tiny amount of analyte which is an important advancement for the measurements of costly or precious samples.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
