Development and Analytical Evaluation of an L-Arginine-Based Optical Sensor for Spectrophotometric Detection of Cu(II) Ions in Water Samples

Abstract

The arginine ligand's analytical performance as a photochemical sensor for the determination of Cu (II) ions was next assessed. The optimal response for the arginine sensor was obtained at pH 8.79 after the experimental circumstances influencing sensor's reaction were methodically tuned. The wavelength used for spectrophotometric measurements was 655 nm. With relative standard deviation (RSD) values of 0.01% and 0.04% for the arginine sensor, respectively, the sensor demonstrated great repeatability and high photostability, indicating a high degree of analytical precision. Additionally, the developed sensor showed a strong linear response within the analyzed concentration range of Cu (II) ions, together with adequate analytical sensitivity. The influence of potential interfering ions, including Fe (III) ,Ca (II), Ni (II), Co (II), and Cd (II), was tested using a 1:1 molar ratio between Cu (II) ions and the interfering ion, where the results revealed the sensor's strong selectivity toward  Cu (II) ions. Finally, the proposed sensing system was effectively employed to assess the concentration of Cu (II) ions in water samples. The results showed good agreement with those obtained using the arginine sensor as well as with standard certified analytical procedures, indicating the reliability, efficiency, and practical usefulness of the developed photochemical sensing technology in the detection of Cu (II) ions.