Following the method by , with slight modifications, 1.33 g of aluminium chloride (AlCl₃) and 1.77 g of potassium chloride (KCl) were accurately weighed using an analytical balance and transferred to a 100 mL volumetric flask. Seventy mL of deionized water was added, and the flask was capped and shaken vigorously until the precursors dissolved completely. Deionized water was then added to bring the volume to 100 mL. Polyalthia longifolia leaves were cleaned of contaminants, rinsed under running tap water, and dried in an oven at 60°C for 24 hours. After drying, the leaves were ground into a fine powder, sieved for uniformity, and 20 g of the powder was mixed with 200 mL of deionized water in a 500 mL beaker. The mixture was heated to boiling for 30-60 minutes. After cooling, it was filtered using filter paper, and the extract was stored for use as a capping and stabilizing agent.