Simple one pot green synthesis of silver-palladium bimetallic nanoparticles: A fluorescent turn-off sensor for detection of lead ions in environmental water and its photocatalytic activity

• Utilization of simple, ecofriendly, cost effective, benign, readily available, gum extract for synthesis of bimetallic nanomaterial. • First time utility of Green synthesized bi-metallic nanoparticle for Pb 2+ sensing • Bimetallic BG-AgPd-NPs synthesized from gum extract of Bael fruit, an inexpensive nano sensor, shows high selectivity and sensitivity for detection of heavy metals Pb 2+ (1 µM) and Fe 2+ (1 µM) in environmental water. • BG-AgPd-NPs nano sensor furnish qualitative and quantitative detection of metal ion devoid of using extravagant equipment. • Further, the bimetallic BG-AgPd-NPs used as an effective catalyst for dye degradation of Toluidine blue and Rose Bengal. Eco-friendly, simple method was developed for the green synthesis of bimetallic silver-palladium nanoparticles (BG-AgPd-NPs) using bael gum (Aegel marmelos) at ambient temperature. Bael gum aqueous solution acts as reducing agent and stabilizing agent by anchoring on to the nanoparticles through the phytochemical constituents present in it. This approach is inexpensive, environmentally benign, and free of hazardous reagents or solvents. The nano particles demonstrate excellent shelf life and stability for several weeks at room temperature. The synthesized nanoparticle was characterized using UV-visible spectrophotometry, Infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction analytical techniques. The new versatile material BG-AgPd-NPs exhibit remarkable fluorescent characteristic, enabling the detection of metal ion especially Pb 2+ ions under laboratory conditions. The metal ion sensing property of BG-AgPd-NPs was assessed using a series of metal ions. The fluorescence studies exhibit excellent selectivity and sensitivity of the BG-AgPd-NPs towards the detection of Pb 2+ ions. The BG-AgPd-NPs probe showed potential for lead ion detection with a limit of detection (LOD) less than 1 µM, which is superior for the probe produced by greener route in the literature. Additionally, the nanoparticles exhibited excellent catalytic activity for dye degradation of rose bengal (RB) and toluidine blue (TB). BG-AgPd-NPs acts as a better catalyst for degradation of RB dye. The adaptability of the material for detecting metal ions in environmental water was also shown by the fluorescent sensing measurements.