Silver Nanoflowers as an Interfacial Liquid-State Surface Enhanced Raman Spectroscopy (SERS) Sensor for Water Pollution

Abstract

Water pollution has created a critical threat to the environment.‎‎ A lot of research has been done ‎recently to use surface-enhanced Raman spectroscopy (SERS) to detect multiple pollutants in water. This study aims to use Ag colloid nanoflowers as liquid SERS enhancer. Tri sodium phosphate (Na₃PO₄) was investigated as a pollutant using liquid SERS ‎based on colloidal Ag ‎nanoflowers. The chemical method was used to synthesize nanoflowers from silver ‎ions. Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), and X-ray diffractometer (XRD) were employed to characterize the silver nanoflowers. This ‎nanoflowers SERS action in detecting Na₃PO₄ was reported and analyzed concerning both shape and size using a 532 ‎nm laser. We observed that the nanoflower's structure produced strong SERS signals. The increase in the SERS signal is related to ‎the deposition of Na₃PO₄ molecules in the aggregated silver nanostructure ‎in the solution. The concentration of Na₃PO₄ plays a main role in detection since the Raman ‎signal becomes stronger as the concentration increases. The highest phosphate analytical enhancement factor obtained for SERS in colloidal nanoflowers was 1.7×10³ at 0.7×10^-6 M which was the lowest concentration.