eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2025-09-30 22 3 1252 1260 10.13005/bbra/3438 56313 article Soniya Subramanian 1 Kamakshi Sampath Kumar 1 Siva Rajagopal 1 Department of Plant Biology and Plant Biotechnology, Shrimathi Devkunvar Nanalal Bhatt Vaishnav College for Women, Tamil Nadu, India. Nanotechnology has emerged as a versatile field with applications across numerous disciplines. This study focuses on the biosynthesis of iron nanoparticles (FeNPs) using an aqueous extract of Lentinus squarrosulus. The formation of FeNPs was confirmed by a distinct color change at 60°C, followed by spectroscopic analyses, including ultraviolet-visible (UV-Vis) and Fourier-transform infrared (FTIR) spectroscopy. The antibacterial efficacy of FeNPs was assessed against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Streptococcus mutans, Enterococcus faecalis, and Enterobacter aerogenes, demonstrating significant inhibitory activity. Additionally, FeNPs exhibited notable photocatalytic degradation of Methylene Blue, Fast Green, and Congo Red dyes, highlighting their potential for wastewater treatment. The findings suggest that FeNPs synthesized via Lentinus squarrosulus could be valuable in biomedical applications and environmental remediation. https://www.biotech-asia.org/vol22no3/photocatalytic-and-antibacterial-activity-of-iron-nanoparticles-synthesized-from-lentinus-squarrosulus-against-human-pathogens/ Antibacterial activity; Dye degradation; Iron nanoparticles; Lentinus squarrosulus; Photocatalytic activity; Wastewater treatment