Biogenic aluminium nanoparticles synthesized from Terminalia chebula seed extract: characterization and exploration of their antiproliferative, antimicrobial and biosensing potential

The green synthesis of aluminium nanoparticles (Al-NPs) via aqueous extract of Terminalia chebula was used to evaluate the structural, biological and sensing applications of the synthesized nanoparticles. Nanoparticle development was confirmed by UV–Visible spectroscopy, showing a typical absorption peak at 300 nm. Fourier transform infrared spectroscopy (FTIR) identified key biomolecules involved in reduction and stabilization, including polysaccharides (C–O–C at 1044 cm − 1 ), proteins/peptides (amide I band at 1660 cm − 1 ) and phenolic compounds (O–H bending at 1328 cm − 1 ), with additional bands indicating the presence of alkenes and aromatic groups. Scanning electron microscopy (SEM) revealed irregular, spherical, leaf-like aggregates measuring 30 to 80 nm, while Energy Dispersive X-ray spectroscopy (EDX) established elemental proportion consistent with aluminium oxide, with Carbon, oxygen and aluminium present at 51.9%, 23.9% and 24.5% by weight, respectively. The biological activity of Al-NPs was demonstrated through dose-dependent antiproliferative effects against A549 lung carcinoma cells with an IC₅₀ value of 72.04 µg/mL, assessed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Biogenic Al-NPs treated cells demonstrated orange-to-red fluorescence, indicates the presence of condensed and fragmented nuclei using Acridine Orange and Ethidium Bromide (AO/EB) assay, indicating apoptosis. The antibacterial efficacy of the biogenic Al-NPs was evaluated using Resazurin Based Microplate assay. The nanoparticles exhibited minimum inhibitory concentration (MIC) values of 1250, 625, 312, and 312 µg/mL and minimum bactericidal concentration (MBC) values of 2500, 1250, 312, and 625 µg/mL against Staphylococcus aureus , Salmonella ebony , Escherichia coli , and Pseudomonas aeruginosa , respectively, demonstrating enhanced activity against Gram-negative bacteria. Furthermore, the Al-NPs exhibited sensitive optical glucose sensing, with UV–Visible spectra showing a linear decrease in plasmonic absorption at 300 nm over glucose concentrations of 1–22 mM. These results highlight the potential of T. chebula mediated Al-NPs as multifunctional nanomaterials for biomedical and biosensing applications.