Recyclable and ultrasensitive SERS sensing platform: Deposition of atomically precise Ag152 nanoclusters on surface of plasmonic 3D ZnO-NC/AuNP arrays.

• Atomically precise Ag 152 nanoclusters (~2 nm) are introduced into 3D arrays structure. • Au nanoparticle (AuNP) with single particle size are prepared as AuNP monolayer film. • The ZnO-NC/Au/Ag 152 3D SERS substrate has high density of hot spots. • The ZnO-NC/Au/Ag 152 substrate exhibits the capability of ultra-sensitive detection. • The substrate can achieve rapid self-cleaning and recycling through photocatalysis. It is well known that the intensity and density of hot spots directly determine the surface-enhanced Raman scattering (SERS) performance of a substrate. In this work, we proposed a new strategy to improve the density of hot spots of a SERS substrate by innovatively introducing atomically precise Ag nanoclusters (Ag 152 (SCH 2 CH 2 Ph) 60 , ~2 nm). First, a 30 nm gold nanoparticle (AuNP) film in conjunction with hexagonal zinc oxide nanocone (ZnO-NC) arrays is prepared as a three-dimensional (3D) backbone; these ZnO-NC/AuNP arrays provide numerous anchors to facilitate the loading of Ag 152 nanoclusters, thereby further enhancing the intensity and density of hot spots on the entire substrate. In addition, the ultra-small particle size of the Ag 152 nanoclusters will not cover the original hot spots on the surface of AuNP film during deposition. Thus, the ZnO-NC/Au/Ag 152 3D SERS sensing platform shows the capability of ultra-sensitive detection, and the substrate results in an enhancement factor (EF) of up to 6.48 × 109. More importantly, the prepared substrate can act as an environmentally friendly sensing platform to achieve rapid self-cleaning and recycling through photocatalysis. The present work confirms the application prospects of novel metal nanoclusters in the field of SERS and photocatalysis. [ABSTRACT FROM AUTHOR]