Bi-functional gold nanoparticles composites regulated by graphene quantum dots with various surface states

Abstract

In this work, the graphene quantum dots (GQDsx, x = 1, 2 and 3) with various surface states were synthesized. Subsequently, GQDsx were facially assembled with glycine derivative (G6) and gold nanoparticles (AuNPs), and novel AuNPs/G6/GQDsx composites were achieved. Furthermore, the fluorescence and SERS results showed the strong dependence on the surface state of GQDs excluding the quantum size effects, which demonstrated the close relationship between the energy transfer efficiency of photoexcited GQDsx and AuNPs. In addition, in comparision with the crystal violet (CV)’ SERS response on GQDsx and AuNPs/G6/GQDsx substrate, it was indicated that the electromagnetic fields effect of AuNPs/G6/GQDsx was also closely related to the surafce state of GQDs. Moreover, the synergetic effect of AuNPs with GQDsx was beneficial to improve the SERS response of AuNPs/G6/GQDsx substrate.

Keywords

• Graphene quantum dots
• Surface state
• Fluorescence
• SERS response
• Crystal violet