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 sp2 grains surrounded by disordered regions are obtained by lowering the growth temperature from the standard 1070 °C to 700 °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

Lisi N.;Buonocore F.;Chierchia R.;
2022-01-01

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 sp2 grains surrounded by disordered regions are obtained by lowering the growth temperature from the standard 1070 °C to 700 °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.
2022
2D materials
Charge transfer
GERS
Graphene enhanced Raman spectroscopy
Nanocrystalline graphene
SERS
Surface-enhanced Raman spectroscopy
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/20.500.12079/66748
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 6
social impact