Biosynthesis of multifunctional silver nanoparticles using a Penicillium verrucosum RPF011 extract for antibacterial and anticancer applications

This study reports the green synthesis of silver nanoparticles (PV-Ag NPs) using a pigment-producing environmental fungus, Penicillium verrucosum (PV) RPF011, as a biological reducing and stabilizing agent. The formation of nanoparticles was initially evidenced by a distinct color change from light to dark brown, corresponding to the reduction of Ag⁺ ions, and was further confirmed by UV–visible spectroscopy showing a characteristic surface plasmon resonance peak at 433 nm. Fourier transform infrared (FTIR) analysis indicated the involvement of proteinaceous biomolecules in the reduction and capping processes, ensuring nanoparticle stability. X-ray diffraction (XRD) patterns revealed the crystalline nature of the synthesized nanoparticles, while high-resolution transmission electron microscopy (HR-TEM) analysis demonstrated that the PV-Ag NPs were predominantly spherical and polydisperse, with an average particle size of 78 ± 2 nm. The biologically synthesized nanoparticles exhibited potent antibacterial activity against clinically relevant pathogens, including Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae. Furthermore, in vitro cytotoxicity assays revealed significant anticancer activity against the human lung carcinoma A549 cell line, with an IC50 value of 53.22 ± 1.5 µg/mL. The enhanced bioactivity of PV-Ag NPs can be attributed to their nanoscale dimensions and the presence of bioactive capping agents derived from the fungal extract. Overall, the findings highlight the potential of P. verrucosum-mediated silver nanoparticles as an eco-friendly and cost-effective nanoplatform with dual therapeutic applications in antimicrobial and anticancer treatments. This study underscores the promise of fungal-mediated nanotechnology in developing novel nano-drug formulations for managing infectious diseases and lung cancer. Graphical abstract