Fluorescent Biosensor for the Detection of Biological Analytes in Aqueous Solutions

Bahloul, Haneen Ghanem; Abdul Farhani, Bassam Faroun

doi:10.29350/qjps.2026.192136

Fluorescent Biosensor for the Detection of Biological Analytes in Aqueous Solutions

10.29350/qjps.2026.192136

Volume 31, Special
Summer 2026

Document Type : Chemistry

Authors

Haneen Ghanem Bahloul

Bassam Faroun Abdul Farhani

University of Al-Qadisiyah – College of Science

Abstract

ABSTRACT
An easy and cost-effective technique was adopted to synthesize tannic acid-capped AgNPs and to develop a fluorescent silver sensor system to detect ferric ion (Fe³⁺) in water. The AgNPs were characterized using UV-Vis absorption, FTIR, EDX, and XRD. The AgNPs in this study were strongly fluorescent with an excitation and emission maximum of 363 and 444 nm, respectively. Fluorescence of nanoparticles was quenched in the existence of Fe³⁺ions relative to other metal ions, thus indicating a good selectivity of the nanoparticles for ferric ions. A linear regression was obtained with a correlation coefficient (R²) of 0.995 for concentrations ranging between 50-250 µM of Fe³⁺. The limit of detection (LOD) was 0.207968 µM. The findings show that AgNPs capped with tannic acid can be used as a simple, sensitive, and selective fluorescent probe for the detection of Fe³⁺ ions in water.