<p>The co-precipitation technique was used to prepare the luminol-modified silica nanoparticles (Luminol-SiO₂ NPs) of the material, which was used as the highly selective Ag⁺ ion detecting fluorescent nanosensors in aqueous solution. Being encapsulated in the silica matrix, the luminol Molecules are also highly photostable and have a high loading capacity hence, highly amplifying the fluorescent response. When Ag⁺ ions are added, the fluorescence is obviously quenched by forming a strong interaction between Ag⁺ and the active sites of luminol, which causes a high efficiency of non-radiative electron transfer. The system was also very sensitive, with a low detection limit (LOD) of 4.0x10^−&#xa0;8 mol.L^−&#xa0;1. The sensor was also able to work well in real water samples spiked with Ag⁺ and gave close to 100 percent recovery. The findings indicate that Luminol-SiO₂ nanosensor can be used in environmental monitoring and traceable concentration detection of silver ions.</p> Graphical abstract <p></p>