Photochemical-assisted deposition of Ag nanoparticles on α-Fe2O3 snowflakes for ultra-sensitive SERS detection of nitrofurazone

Surface enhanced Raman Spectroscopy (SERS) stands as an exceptionally sensitive spectroscopic method extensively employed in various research fields, such as environmental monitoring, molecular diagnosis, food safety, and biochemistry. The study of semiconductor/noble-metal based SERS substrates has exponentially increased due to the apparent enhancement of Raman signal intensity by the synergistic utilization of electromagnetic and charge transfer mechanisms through the enhanced plasmonic and vibronic characteristics. Constructing an optimal assembly as a SERS substrate is the purpose pursued by many researchers. Herein, we present a promising semiconductor/noble-metal nanocomposite by photoreduction of silver nanoparticles (Ag NPs) on the hydrothermally synthesized hierarchical α-Fe2O3 snowflakes (SFs) through the green photoreduction technique. Various analytical characterization methods were employed to examine the physiochemical characteristics of the α-Fe2O3-SFs/Ag. The presented α-Fe2O3-SFs/Ag based SERS substrate enables ultra-sensitive detection of antibiotic nitrofurazone (NFZ) with the extremely low limit of detection of 3.12 × 10–14 M, the utmost enhancement factor of 3.08 × 1012, satisfactory uniformity and high reproducibility. The excellent SERS activity of the synthesized α-Fe2O3-SFs/Ag nanocomposite is owing to the generation of innumerable hotspots and the effective charge transfer for sublime Raman signal enhancement through the synergism of electromagnetic and charge transfer mechanisms. The α-Fe2O3-SFs/Ag based SERS substrate shows high recovery rate in the range of 89.9–98.78 % for detection of NFZ in the pond water and the fish feed solution for real-sample analysis. The proposed strategy in our study can efficiently detect trace amounts of NFZ in physiological circumstances and could contribute to the advancement of ultra-sensitive SERS based detection techniques.