Selective Detection of Silver Ions Based on Resonance Rayleigh Scattering Spectrometry Using Colloidal Silica Nanoparticles

Colloidal silica or silicon dioxide nanoparticles (SiO2 NPs) are extremely amorphous nanomaterials owing spherical shape. These nanoparticles have gained much interest due to their usage in various fields; going from the industrial domain to the biomedical field. In this study, the synthesis of SiO2 NPs was investigated and optimized by varying two essential parameters including the type of silica precursor and the concentration of sodium hydroxide. The suitable nanoparticles were formed according to the best silica precursor (Colloidal Silica) and the optimum NaOH concentration (C = 100 mM). The applicability of the prepared nanoparticles was performed for the detection of silver ions in the concentration range between 5 and 300 μM based on resonance Rayleigh scattering (RRS) spectrometry. The limit of detection obtained was equal to 130 nM and the recovery percentage was between 98.4 and 100.4%. The detection of silver ions based on RRS technique was find to be easy to manipulate, simple and fast with low cost, compared to the usual techniques used as chromatography and calorimetric techniques.