Au@Ag/ultrathin g-C3N4/graphene composite surface-enhanced Raman scattering film with stable, flexible and self-cleaning capability

Flexibility and self-cleaning are the main research hot-spots in the development of plasma substrates for practical applications in Surface-enhanced Raman scattering (SERS) at present. In this study, a flexible composite Au@Ag/ultrathin g-C3N4/Graphene (AUG) film based on PDMS film was reported and used as a highly sensitive SERS substrate for the detection of rhodamine 6G (R6G) molecules. The Au@Ag nanosphere array formed by self-assembly provided dense hot-spots, the ultrathin g-C3N4 enabled the composite to possess excellent photocatalytic ability, and the graphene enhanced SERS detection and photocatalytic performance while improving the stability of the composite film. The results showed that the AUG flexible composite film had a detection limit of 10-12 M for R6G molecules. After 10 photocatalytic cycles of testing, the composite film maintained 83 % of SERS activity. Benefiting from the graphene covering the surface, the composite films showed only a 5 % decrease in SERS detection performance after 30 days of storage in air. The facile fabrication process of AUG composite film enables it to be an outstanding candidate for the flexible, inexpensive, and stable wearable SERS sensing systems.

Automated summary

Flexibility and self-cleaning are important areas of research in the development of plasma substrates in Surface-enhanced Raman scattering (SERS). This study presents a flexible composite Au@Ag/ultrathin g-C3N4/Graphene (AUG) film, based on a PDMS film, used as a highly sensitive SERS substrate for detecting rhodamine 6G (R6G) molecules. The AUG flexible composite film displayed a detection limit of 10-12 M for R6G molecules, maintained 83% of SERS activity after 10 photocatalytic cycles, and had only a 5% decrease in SERS detection performance after 30 days of storage in air. The facile fabrication process makes the AUG composite film an excellent candidate for flexible, inexpensive, and stable wearable SERS sensing systems.