Electrochemical and antimicrobial activity of tellurium oxide nanoparticles

• TeO2 NPs synthesized without using any catalyst by chemical vapour deposition method.
• The growth temperature was 410 °C with continuous flow of O2.
• TeO2 NPs have anti-bacterial activity against E. coli, K. pneumoniae and S. aureus while enhances the growth of S. pyogenes.
• TeO2 shows maximum redox current at pH 7 for phosphate buffer solution.

Thin film of tellurium oxide (TeO2) has been synthesized by chemical vapour deposition method onto indium tin oxide (ITO) coated glass substrate without using any catalyst. XRD pattern of TeO2 thin film suggests that the structure of TeO2 changes from amorphous to crystalline (paratellurite) on dispersing into deionized water. Zeta potential measurement reveals a positive surface potential of 28.8 mV. TEM images shows spherical shaped TeO2 nanoparticles having average particle size of 65 nm. Electrochemical studies of TeO2/ITO electrode exhibit improved electron transfer owing to its inherent electron transfer property at pH 7.0 of phosphate buffer. Antimicrobial activity of TeO2 has been studied for gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and gram negative (Escherichia coli and Klebsiella pneumoniae) bacterial and fungal strains (Aspergillus nizer and Candida albicans). These studies suggest that the TeO2 NPs inhibit the growth of E. coli, K. pneumoniae and S. aureus bacteria, whereas the same particles enhance the growth of S. pyogenes bacteria.