The development of ultrasensitive and biocompatible Surface-Enhanced Raman Spectroscopy (SERS) substrates, able to provide uniform and reproducible signals, has become a focus of study in the last decade. Graphene, with his advantageous properties, such as photoluminescence quenching of fluorescent dyes, chemical inertness and biocompatibility, allows to overcome many important limitations of conventional metal SERS substrates. In this work, we develop ultrasensitive graphene substrates by ethanol Chemical Vapor Deposition (CVD). Large-area thin films composed of nanosized sp(2) grains surrounded by disordered regions are obtained by lowering the growth temperature from the standard 1070 degrees C to 700 degrees C. Our substrates are able to detect trace amounts of molecules, down to 6.10(-11) M, which is the lowest concentration that has been achieved in Graphene-Enhanced Raman Spectroscopy (GERS) with rhodamine 6G (R6G) as probe molecule. This outstanding result is attributable to two main features: i) more efficient charge transfer due to the energy level matching between R6G and the nanocrystalline graphene film; ii) large number of grain boundaries acting as "trapping sites" for the molecules.

Nanocrystalline graphene for ultrasensitive surface-enhanced Raman spectroscopy

Faggio, G
;
Messina, G
2022

Abstract

The development of ultrasensitive and biocompatible Surface-Enhanced Raman Spectroscopy (SERS) substrates, able to provide uniform and reproducible signals, has become a focus of study in the last decade. Graphene, with his advantageous properties, such as photoluminescence quenching of fluorescent dyes, chemical inertness and biocompatibility, allows to overcome many important limitations of conventional metal SERS substrates. In this work, we develop ultrasensitive graphene substrates by ethanol Chemical Vapor Deposition (CVD). Large-area thin films composed of nanosized sp(2) grains surrounded by disordered regions are obtained by lowering the growth temperature from the standard 1070 degrees C to 700 degrees C. Our substrates are able to detect trace amounts of molecules, down to 6.10(-11) M, which is the lowest concentration that has been achieved in Graphene-Enhanced Raman Spectroscopy (GERS) with rhodamine 6G (R6G) as probe molecule. This outstanding result is attributable to two main features: i) more efficient charge transfer due to the energy level matching between R6G and the nanocrystalline graphene film; ii) large number of grain boundaries acting as "trapping sites" for the molecules.
2D materials
Surface-enhanced Raman spectroscopy
SERS
Nanocrystalline graphene
Graphene enhanced Raman spectroscopy
GERS
Charge transfer
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12318/130686
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 1
social impact