Home
1
1 Department of Physics, Chennai Institute of Technology, Chennai-600069, Tamilnadu, India.
2 Department of Chemistry, Chennai Institute of Technology, Chennai-600069, Tamilnadu, India.
3 PG and Research Department of Physics, Thanthai Hans Rover College (Autonomous), Perambalur – 621 220, Tamilnadu, India.
4 Department of Physics, Bharath Institute of Science & Technology, Bharath Institute of Higher Education and Research, Chennai-600073, Tamilnadu, India.
5 Department of Physics, Academy of Maritime Education and Training, Chennai, Tamil Nadu 603112, India.
* Correspondence: ssenthil_14@yahoo.co.in
Journal of Optoelectronic and Biomedical Materials 2026, 18(2),16-44; https://doi.org/10.67229/JOBM16297
Picolinic acid copper sulfate (PACS) crystals have been prepared by slow evaporation method and their structural characteristics, optical characteristics, nonlinear optical (NLO) characteristics, as well as antibacterial characteristics are systematically examined. X-ray diffraction analysis in the form of powder revealed the crystalline structure of PACS that is monoclinic in nature and possesses good phase purity. The existence of typical functional groups and metal-ligands interactions within the crystal lattice were confirmed using Raman and FTIR spectroscopy. The optical investigation by the UV-Vis spectroscopy has shown that the band gap is about 1.8 eV which means the material is transparent in the visible spectrum and it can be used in the field of optoelectronics. The field-emission scanning electron microscopy revealed a homogenous crystal morphology with properly developed surfaces. The Z-scan method was used to measure nonlinear optical properties, and the results obtained indicate that the nonlinear refractive index of the material was n2 = 3.51 x 10-10 cm2/W, the nonlinear absorption coefficient was b = 3.81 x 10-6 cm/W, and the third-order susceptibility was χ⁽³⁾ = 4.77 x 10-8 esu, which is a good indicator of strong NLO activity. Antibacterial tests on Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli showed high zones of inhibition which showed potential promising antimicrobial activity. The optical and antibacterial dual functionality indicates that PACS crystals could be considered as multifunctional in the applications in photonic equipment, optical limiters and antimicrobial coating.
