Testing of antibacterial efficacy of CuO nanoparticles by methylene blue reduction test against Bacillus cereus responsible for food spoilage and poisoning

ABSTRACT

The synthesis of CuO nanoparticles was carried out by hydro-thermal method in Teflon-lined stainless steel pressure autoclave at 180°C ± 2°C for 12 h. The precursor and reducing agent used was 0.2 M copper acetate and 1 M urea, respectively. Characterisation of CuO powder was carried out by UV–Visible Spectroscopy and Scanning Tunnelling Microscopy (STM). The absorption spectrum was found to be at 339 nm and its band gap about 3.65 eV and STM image showed cluster morphology on the surface at 200 nm. The qualitative determination of antibacterial efficacy of CuO NPs against Bacillus cereus was performed by methylene blue reduction test. It was evident that the synthesised CuO NPs showed antibacterial activity against B. cereus. However, quantitative assay and probable antibacterial mechanism of CuO NPs must be further investigated. This paper reveals the potential of CuO NPs in food protection, especially food products getting contaminated by B. cereus.

KEYWORDS:

• Copper oxide nanoparticles
• hydro-thermal method
• MBRT
• Bacillus cereus

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Jayant Pawar http://orcid.org/0000-0002-6995-3534