ZnO/graphene/Ag composite as recyclable surface-enhanced Raman scattering substrates

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman scattering (SERS) is a powerful technique for ultrasensitive molecular detection.
• Developing cost-effective and recyclable SERS substrates is crucial for practical applications.
• Zinc oxide (ZnO) nanostructures offer promising platforms for SERS due to their unique optical and electrical properties.

Purpose of the Study:

• To fabricate and characterize novel SERS-active substrates based on ZnO nanorod arrays decorated with silver (Ag) nanoparticles.
• To investigate the effect of incorporating graphene into the ZnO/Ag hybrid structure on SERS performance.
• To evaluate the recyclability of the developed SERS substrates using photocatalytic properties.

Main Methods:

• ZnO nanorod arrays were synthesized on seed layers.
• Silver nanoparticles were deposited onto ZnO and ZnO/graphene surfaces via photocatalytic deposition.
• Scanning electron microscopy (SEM) and Raman spectroscopy were used for structural and chemical characterization.
• Rhodamine 6G (R6G) was employed as a probe analyte to assess SERS performance.

Main Results:

• The hybrid ZnO/Ag and ZnO/graphene/Ag structures were successfully fabricated and confirmed.
• The SERS detection limit for R6G reached 10^-7 M with an enhancement factor of approximately 1.6×10⁵.
• The ZnO/graphene/Ag substrate exhibited superior SERS activity compared to the ZnO/Ag substrate.
• UV-assisted cleaning demonstrated the effective recyclability of the SERS substrates.

Conclusions:

• The fabricated ZnO/Ag and ZnO/graphene/Ag nanostructures serve as efficient SERS-active substrates.
• The incorporation of graphene significantly enhances the SERS performance.
• The substrates possess excellent recyclability, making them suitable for sustainable sensing applications.