Abstract
In this research work, Bi
2
O
3
, Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO nanocomposites have been synthesized via an eco-friendly green synthesis technique, solgel route and co-precipitation method respectively for the assessment of antibacterial activity as well as in vivo toxicity. The XRD patterns confirm the formation of Bi
2
O
3
, Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO nanocomposites showing monoclinic structures. Crystallite size and lattice strain are calculated by Scherrer equation, Scherrer plot and Willimson Hall plot methods. Average crystallite size measured for Bi
2
O
3
, Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO nanocomposites by Scherrer equation, Scherrer plot and WH-plot methods are (5.1, 13.9, 11.5)nm, (5.4, 14.2, 11.3)nm and (5.2, 13.5, 12.0)nm respectively. Optical properties such as absorption peaks and band-gap energies are studied by UV–vis spectroscopy. The FTIR peaks at 513 cm
−1
, 553 cm
−1
and 855 cm
−1
confirms the successful synthesis of Bi
2
O
3
, Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO nanocomposites. The antibacterial activity of synthesized Bi
2
O
3
, Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO nanocomposites is examined against two gram-negative (
Escherichia coli
and pseudomonas) as well as gram-positive bacteria (
Bacillus cereus
and
Staphylococcus aureus
) at dose 25 mg/kg and 40 mg/kg by disk diffusion technique. Zone of inhibition for Bi
2
O
3
, Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO at dose 40 mg/kg against
E. coli
(gram − ve) are 12 mm, 17 mm and 18 mm respectively and against
Pseudomonas
(gram − ve) are 28 mm, 19 mm and 21 mm respectively. While the zone of inhibition for Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO at dose 40 mg/kg against
B. cereus
(gram + ve) are 8 mm and 8.5 mm respectively and against
S. aureus
(gram + ve) are 5 mm and 10.5 mm respectively. These amazing results reveal that Bi
2
O
3
, Bi
2
O
3
/GO and Bi
2
O
3
/CuO/GO nanocomposite as a kind of antibacterial content, have enormous potential for biomedical applications. In addition, the in vivo toxicity of synthesized Bi
2
O
3
/CuO/GO nanocomposite is investigated on
Swiss Albino
mice at dose of 20 mg/kg by evaluating immune response, hematology and biochemistry at the time period of 2, 7, 14 and 30 days. No severe damage is observed in mice during whole treatment. The
p
value calculated by statistical analysis of hematological and biochemistry tests is nonsignificant which ensures that synthesized nanocomposites are safe and non-toxic as they do not affect mice significantly. This study proves that Bi
2
O
3
/CuO/GO nanocomposites are biocompatible and can be explored further for different biomedical applications.