One-pot facile synthesis of hexagonal Bi2Te3 nanosheets and its novel nanocomposites: Characterization, anticancer, antibacterial, and antioxidant activities

Bismuth Telluride (Bi2Te3) layered structure results in extraordinary features in diagnostic and therapeutic applications. However, Bi2Te3 synthesis with reliable stability and biocompatibility in biological systems was the major challenge that limited its biological application. Herein, reduced graphene oxide (RGO) or graphitic carbon nitride (CN) nanosheets were incorporated into Bi2Te3 matrix to improve exfoliation. Bi2Te3 nanoparticles (NPs) and its novel nanocomposites (NCs): CN@Bi2Te3 and CN-RGO@Bi2Te3 were solvothermally synthesized, physiochemically characterized and assessed for their anticancer, antioxidant, and antibacterial activities. X-ray diffraction depicted Bi2Te3 rhombohedral lattice structure. Fourier-transform infrared and Raman spectra confirmed NC formation. Scanning and transmission electron microscopy revealed 13 nm thickness and 400-600 nm diameter of hexagonal, binary, and ternary nanosheets of Bi2Te3-NPs/NCs. Energy dispersive X-ray Spectroscopy revealed the presence of Bi, Te, and carbon atoms in the tested NPs with negatively charged surfaces as depicted by zeta sizer. CN-RGO@Bi2Te3-NC displayed the smallest nanodiameter (359.7 nm) with the highest Brunauer-Emmett-Teller surface area and antiproliferative activity against MCF-7, HepG2 and Caco-2. Bi2Te3-NPs had the greatest scavenging activity (96.13 ± 0.4%) compared to the NCs. The NPs inhibitory activity was greater against Gram-negative bacteria than that of Gram-positive bacteria. Integration of RGO and CN with Bi2Te3-NPs enhanced their physicochemical properties and therapeutic activities giving rise to their promising capacity for future biomedical applications.