Plasma-Assisted Synthesis of Surfactant-Free and D-Fructose-Coated Gold Nanoparticles for Multiple Applications

The excellent optical properties of gold nanoparticles (AuNPs) make them promising for numerous applications. Herein, we present a facile synthesis of both surfactant-free (SF−AuNPs) and non-toxic D-fructose (DF)-coated gold nanoparticles (DF−AuNPs) via the plasma–liquid interactions (PLIs) method. Moreover, we demonstrate that both SF−AuNPs and DF−AuNPs are potential candidates for trace detection via surface-enhanced Raman scattering (SERS) and catalytic degradation of toxic dyes. However, SF−AuNPs have superior SERS and catalytic performance compared to the DF−AuNPs due to their surfactant-free nature. Moreover, SF−AuNPs have also been shown to quench the fluorescence of analyte molecules, making their SERS-based trace detection more efficient. In particular, SERS enhancement of rhodamine 6G (R6G) and catalytic reduction of a toxic dye methylene blue (MB) have been explored.