Ayah O. Abouligheeb et al. 2026. Development and Analytical Evaluation of an L-Arginine-Based Optical Sensor for Spectrophotometric Detection of Cu(II) Ions in Water Samples. Journal of Insights in Basic and Applied Sciences. 2, 3 (Sep. 2026), 799–806. DOI:https://doi.org/10.65421/jibas.v2i3.207.