Addressing the challenging stabilization of colloidal silver suspensions as an optimization tool for efficient Surface Enhanced Raman Scattering
Year: 2025
Type: article
Abstract: Surface-enhanced Raman Scattering (SERS) is a highly sensitive technique for detecting trace amounts of analytes, widely used in diagnostics, environmental monitoring and chemical analysis. A key challenge when using nanocolloidal SERS substrates is the induced aggregation of plasmonic nanoparticles (NPs), necessary for "hot-spot" formation, which conventionally causes a sharp maximization of SERS scattering. Unfortunately, these aggregates are unstable in the solution, as they tend to grow until they eventually precipitate, followed by a consequent rapid decrease of the SERS signal. Current stabilizers, such as surfactants, polymers and inorganic compounds, focus on NPs stability rather than preserving the SERS signal for specific analytes, highlighting the need for improved stabilization strategies. This work explores the ability of a cationic surfactant, the hexadecyltrimethylammonium bromide (CTAB), as a delaying factor for the decay of the SERS signal of a representative analyte (methylene blue, MB), while promoting optimal "hot-spot" formation. In addition, an ionic liquid, the imidazolium chloride, is investigated as a dual action agent that causes aggregation retardation as well as stabilization of the SERS signal.
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,200
OpenAlex ID: W4411137453