A Violet to Greenish Fluorogenic Ratiometric Probe for Selective and Sensitive Detection of Phosphate (PO ₄ ³⁻ ) Ion

Phosphate (PO₄ ^3-) ions play pivotal parts in the biological system as it provides key nutrients indispensable for sustaining life and also has vast applications in the industrial fields. However, surplus amount of PO₄ ^3- ion can be very hazardous and cause serious health issues in various aspects of life, which makes the targeted and precise identification of PO₄ ^3- ion essential. In this study, we have chosen an amino-imidazole-based probe, 2-(2-aminophenyl)-1H-benzimidazole (IMIDA), which undergoes distinct photophysical change, resulting in a significant violet to greenish fluorescence enhancement in the presence of PO₄ ^3- ion. The probe IMIDA exhibits excellent sensitivity, selectivity, and prompt response towards PO₄ ^3- ion having detection and quantification limit in the nM range, which makes it commendable for its monitoring. A handy paper strip and smartphone-based detection strategy are executed for the on-spot detection of PO₄ ^3- ion. The applicability of the probe is further illustrated by the detection of PO₄ ^3- ion in environmental conditions by using different water samples. Thus, the present study provides a robust, simple, and efficient scaffold for the detection of PO₄ ^3- ion, extending opportunities for advancement in environmental monitoring, industrial quality control, and biomedical diagnostics.