Enhanced Cytotoxic Efficacy of Ocimum basilicum Leaf Extract-Mediated TiO₂ Nanocrystals

Breast cancer has become a global health burden, and therefore requires necessitating action against the development of affordable, target-oriented, and safe chemotherapeutic agents to mitigate its prevalence worldwide. In the present report, titanium oxide (TiO₂) nanocrystals (NCs) were synthesized using the green route utilizing Ocimum basilicum leaf extract (OBLE). X-ray diffraction (XRD) studies revealed that TiO₂ NCs exhibit tetragonal crystal configuration with anatase-type symmetry with space group. The phenolic groups (–OH) present in OBLE were detected as the bend appeared at 3420 cm^{− 1} in the infrared spectrum. The characteristic hump positioned at 331 nm in the UV–visible diffuse reflectance spectrum (UV–DRS) of biosynthesized TiO₂ NCs confirmed the formation of nanoparticles and the optical band gap of TiO₂ NCs was found to be 3.41 eV as evaluated from Tauc’s plot. The surface morphology of TiO₂ NCs showed minute agglomeration with an average particle size of 11.8 ± 0.66 nm as obtained from statistical analysis of the particle size distribution. The cytotoxic activity of TiO₂ NCs was investigated against MDA–MB 231 cancer cells and dose-dependent cell inhibition was observed with a low IC₅₀ value of 13.35 µg/mL after 48 h of incubation time. The present study underscores the remarkable cytotoxicity demonstrated by TiO₂ NCs against breast cancer cell lines.