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Universal Fabrication of Highly Efficient Plasmonic Thin‐Films for Label‐Free SERS Detection

2021; Wiley; Volume: 17; Issue: 33 Linguagem: Inglês

10.1002/smll.202100755

1613-6829

Sara Gullace, Verónica Montes‐García, Víctor F. Martín, David Larios, Valentina Girelli Consolaro, F. Obelleiro, Giuseppe Calogero, Stefano Casalini, Paolo Samorı́,

Advanced Nanomaterials in Catalysis

Abstract The development of novel, highly efficient, reliable, and robust surface enhanced Raman scattering (SERS) substrates containing a large number of hot spots with programmed size, geometry, and density is extremely interesting since it allows the sensing of numerous (bio‐)chemical species. Herein, an extremely reliable, easy to fabricate, and label‐free SERS sensing platform based on metal nanoparticles (NPs) thin‐film is developed by the layer‐by‐layer growth mediated by polyelectrolytes. A systematic study of the effect of NP composition and size, as well as the number of deposition steps on the substrate's performance, is accomplished by monitoring the SERS enhancement of 1‐naphtalenethiol (532 nm excitation). Distinct evidence of the key role played by the interlayer (poly(diallyldimethylammonium chloride) (PDDA) or PDDA‐functionalized graphene oxide (GO@PDDA)) on the overall SERS efficiency of the plasmonic platforms is provided, revealing in the latter the formation of more uniform hot spots by regulating the interparticle distances to 5 ± 1 nm. The SERS platform efficiency is demonstrated via its high analytical enhancement factor (≈10 6 ) and the detection of a prototypical substance(tamoxifen), both in Milli‐Q water and in a real matrix, viz. tap water, opening perspectives towards the use of plasmonic platforms for future high‐performance sensing applications.