Centrifugation-induced assembly of dense hotspots based SERS substrate for enhanced Raman scattering and quenched fluorescence. (4th June 2022)

• Record Type: Journal Article
• Authors: Su, Dan; Zhang, Xiao-Yang; Chen, Xia-Yao; Wang, Shan-Jiang; Wan, Qing-Dian; Zhang, Tong
• Is Part Of: Nanotechnology. Volume 33:Number 23(2022)
• Publication Date: 2022-06-04
• Subjects: sintering-resistant -- SERS -- plasmonic nanostructure -- dense hotspots; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ac57d3
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Hanging (aggregation stuck to the centrifugal tube) in the centrifugation process is always regarded as an unwanted condition. In this work, we develop a centrifugation-induced assembly of dense hotspots surface-enhanced Raman scattering (SERS) substrates from the hanging phenomenon. We discovered interesting sintering-resistant behavior (maintain the sharp nanotip features) of star-like Au nanoparticles after centrifugation-induced assembly, which is in stark contrast with the sintering phenomenon of sphere-like nanoparticles. We also found that one side of centrifugal-induced Au assemblies is two-dimensional (2D, root mean square (rms) roughness down to ∼10 nm), while the other is three-dimensional (3D, rms roughness more than 100 nm). The close-packed feature of the Au assemblies makes them candidates as dense hotspots based SERS substrates. Through systematic investigation of SERS performance of centrifugation-induced assemblies with different morphology (star-like and sphere-like, 2D and 3D), it was found that the 3D side of star-like Au nanoparticles assembly exhibits the highest SERS enhancement together with quenched fluorescence. The star-like SERS substrate also displays high detection uniformity (with 10 −7 M Rhodamine 6G) and a low detection limit (down to 10 −12 M Rhodamine 6G).