Green synthesis of La 2 O 3 –LaPO 4 nanocomposites using Charybdis natator for DNA binding, cytotoxic, catalytic, and luminescence applications

• Published in: Green processing and synthesis Vol. 13; no. 1
• Main Authors: Sivaraman, Rajendran Muthukumar, Gracia, Kirubaharan Daphne Jacinth, Thavamani, Seth Sheeba, Amaladhas, Thomas Peter, Devanesan, Sandhanasamy, AlSalhi, Mohamad Saleh
• Format: Journal Article
• Language: English
• Published: 01.10.2024
• ISSN: 2191-9550; 2191-9550
• DOI: 10.1515/gps-2024-0092

A one-step biosynthetic pathway for the fabrication of La 2 O 3 –LaPO 4 nanocomposites (NCs) was developed, employing Charybdis natator . The structure and phase changes of the NCs were confirmed, and their diverse applications were explored. The peaks at 206, 332, and 442 nm in UV-DRS studies confirmed the formation of La 2 O 3 –LaPO 4 NCs. Fourier transform infrared spectral analysis revealed La–O stretching at 716 cm −1 and the presence of PO 4 3 − {\text{PO}}_{4}^{3-} bands at 532, 560, 578, and 618 cm −1 . X-ray diffraction patterns showed a hexagonal phase of La 2 O 3 with peaks at 2 θ 11.04 and 28.57 and monoclinic LaPO 4 phases at 2 θ = 18.79 and 41.88. X-ray photoelectron spectroscopy data showed binding energy peaks at 836.04 and 852.77 eV, corresponding to 3d 5/2 and 3d 3/2 of the lanthanum. The average particle size from HR-TEM analysis was 28.95 nm after annealing at 800°C and SAED patterns confirmed their crystalline nature. The high affinity of the NCs towards ctDNA was established by a binding constant value of 2.08 (mg·mL −1 ) −1 . Under UV exposure, 96% degradation efficiency for methyl orange within 120 min at pH 4 was displayed, with a rate constant of 2.72 × 10 −2 min −1 affirming their photocatalytic potential. Their biocompatibility was assessed through MTT assay and luminescence characteristics were evaluated.