Rapid and effective synthesis of fern-shaped silver nanodendrites decorated with gold nanoparticles to improve SERS detection of endosulfan

The advancement of surface-enhanced Raman scattering (SERS) nanosubstrates is a key goal in research, focusing on improving sensitivity and simplifying fabrication. This study presents a simple method for synthesizing gold/silver nanodendrites (Au/AgNDs) via a redox process at room temperature, enabling the rapid production of highly branched nanostructures in minutes without the need for additional solvents, reducing agents, or stabilizers. Furthermore, by systematically varying the concentration of precursors and the reaction time, it is possible to produce different morphologies for AgNDs. The rough Au/AgNDs surface provides a high density of electromagnetic sites, which benefits molecular analysis using SERS techniques. AgNDs with branch lengths ranging from 1.0 to 10 μm were selected for gold nanoparticle decoration based on governing conditions, including reaction time, reagent concentrations, and temperature. The effectiveness of the Au/AgNDs substrate in detecting endosulfan was evaluated, showing a detection limit (LOD) of 0.087 ppb, quantification limit (LOQ) of 0.284 ppb, and a percentage relative standard deviation (RSD) of 5.61 % based on 18 random measurement locations across five substrates with at least 4 points tested per substrate, indicating good reproducibility. The FDTD method simulated the EM fields on Au/AgNDs, supporting the purely theoretical findings about the ability of these nanomaterials to enhance SERS. These results show that Au/AgNDs are potential SERS substrates for chemical sensing and environmental monitoring.