A Green Synthesis by Pulse Laser Ablation in Liquid to Form Core@Shell Nanoparticles for High- Performance Antibacterial and Antioxidant Agents

Nanoparticles have emerged as promising platforms due to their unique properties. Increasing resistance to antibiotics and antioxidants represents a pressing global health challenge that requires new therapeutic and preventive solutions. This study aimed to prepare new nanoparticles with an inner core of palladium and titanium dioxide and a shell of silicon dioxide by pulse laser ablation in liquid technique, investigate their properties, and subsequently evaluate their antibacterial and antioxidant activities. Their structures and morphological properties were examined, and the results demonstrated the successful preparation of homogeneous nanoparticles with an average size of (20–50) nm. The purity of the material and homogeneous spherical shape were confirmed. It was also observed that the nanoparticles had a maximum absorption peak at 316 nm. Antibacterial activity against Gram-positive and Gram-negative bacteria was evaluated using the agar diffusion method, with the largest inhibition zone being 24.9 mm² and 16.6 mm² at low minimum inhibitory concentrations of less than 100 µg/ml. Antioxidant activity was evaluated, revealing high antioxidant activity at a concentration of 100 µg/mL, which demonstrated a 90% free radical scavenging capacity of the nanoparticles at this concentration. This study confirms the ability of core-shell nanoparticles to enhance the combined properties of these materials, making them effective antibacterial and antioxidant agents, and thus opening new avenues for the development of alternative antibiotic treatments and antioxidants in medical and pharmaceutical applications.