ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Fluorescence quenching-based sensing of Ag⁺ ions via modified silica nanoparticles in aqueous media

Noura H. Harran and Bassam F. Alfarhani

Department of Chemistry/ College of science/ University of Al-Qadisiyah, Al Diwaniyah, Iraq

E-mail: nourhahussain@qu.edu.iq

Received: 24 April 2026  Accepted: 5 June 2026

Abstract:

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^− 8 mol.L^− 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.

Graphical abstract

Keywords: Luminol-SiO2NPs; Nanosensor; Ag+ detection; Fluorescence assay

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05177-7

Chemical Papers 80 (11) 13257–13266 (2026)