Characterization and evaluation of the anti-bacterial activity of facile biosynthesis Zinc oxide nanorods using Spirulina platensis

Abstract

ABSTRACT ZnO nanorods (NRs) were synthesized with Zn(NO3)2, citric acid, and NaOH as precursors and Spirulina platensis as a capping agent. The sol-gel-hydrothermal method was used to synthesize ZnO-NRs with pH adjustment of the reaction to modify its morphology. Furthermore, the products of ZnO-NRs were characterized by FT-IR, UV-Vis UV-DRS, XRD, SEM, and EDS instruments. The characterization result shows crystal and particle size differences when the biosynthetic pH ranges from 7 to 13. The ZnO bandgap energy changed at a certain pH ranging from 3.13 to 3.17 eV. FTIR analysis shows that the stretching of Zn-O occurs at wave number 436 cm−1. The morphological patterns of SEM-EDX showed that the ZnO-NPs were spherical, cube, and nanorods. However, the dominant morphology is nanorods form, where the particle sizes ranged from 120 to 180 nm. The result of the antimicrobial activity test against Staphylococcus epidermidis shows that the maximum inhibition of ZnO-pH 9 was 6–16 mm. The antioxidant test also shows that ZnO-pH 9 had the highest antioxidant content, accounting for 72.1%.