Applied Chemical Engineering

Green synthesized Gracilaria folifera-mediated MgO-ZnO nanocomposite for photocatalytic and anticancer applications

M. Adhithi

Department of Physics, Vellalar College for Women (Autonomous), Erode 638012, Tamil Nadu, India

M. Yogeswari

Department of Physics, Vellalar College for Women (Autonomous), Erode 638012, Tamil Nadu, India

D.D. Padma Priya

Department of Mathematics-Applied Sciences, New Horizon College of Engineering, Bangalore 560103, Karnataka, India

S. Kannappan

Department of Electronics and Communications Engineering, Siddharth Institute of Engineering & Technology, Puttur 517583, Andhra Pradesh, India

K.Vinoth Kumar

Department of Electrical and Electronics Engineering, New Horizon College of Engineering, Bengaluru 560103, Karnataka, India

N.J. Suthan Kissinger

Department of General Studies (Physics Section), Jubail Industrial College, Royal Commission for Jubail, P.O Box 35718, KSA

S. Sivakumar

Department of Physics, Government Arts College (Autonomous), Salem 636007, Tamilnadu, India

B. Sangeetha

Department of Electrical and Electronics Engineering, AVS Engineering College, Salem 636003, Tamilnadu, India

B. Esther Bharathi

Department of Physics, Government Arts College (Autonomous), Salem 636007, Tamilnadu, India

DOI: https://doi.org/10.59429/ace.v9i3.6059

Keywords: green synthesis; Gracilaria folifera; MgO-ZnO nanocomposite; photocatalytic activity; cytotoxicity; HT29 cells; bandgap energy

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Abstract

Gracilaria folifera-mediated MgO-ZnO nanocomposite (GF-MgO-ZnO NC) was synthesized through a green approach utilizing G. folifera extract as a reducing, stabilizing, and biofunctionalizing agent. The structural, optical, photocatalytic, and anticancer properties of the synthesized nanocomposite were systematically investigated. X-ray diffraction analysis confirmed the coexistence of crystalline MgO and ZnO phases, indicating the successful formation of a mixed-oxide nanocomposite with good crystallinity. UV-Visible spectroscopy revealed broad absorption in the UV region and an optical band gap of 4.88 eV, suggesting electronic interactions between the MgO and ZnO components. The photocatalytic performance of GF-MgO-ZnO NC demonstrated effective degradation of methyl orange dye under UV irradiation, which may be associated with improved charge separation within the MgO-ZnO nanocomposite. The anticancer activity evaluated against HT29 colorectal cancer cells using the MTT assay exhibited a concentration-dependent reduction in cell viability, with an IC₅₀ value of 93.23 μg/mL. The observed cytotoxicity may be associated with the synergistic effects of the MgO-ZnO nanocomposite and residual phytochemical species derived from G. folifera; however, the underlying molecular mechanisms were not directly investigated in the present study. These findings demonstrate that the green-synthesized GF-MgO-ZnO NC exhibits moderate photocatalytic activity and concentration-dependent cytotoxicity against HT29 colorectal cancer cells, warranting further investigation for environmental remediation and biomedical applications.

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