Zinc oxide (ZnO) is a crucial material for industries such as rubber production, biomedical applications, and metal surface treatment areas. ZnO has semiconductivity, antimicrobial activity, and UV absorption capability. This material is regarded as a vulcanization activator. Transform this material to a nanoparticle prefers because increasing the materials particle size decreases and surface area occurs in this way. In scientific literature, researchers have attempted to increase the features of ZnO nanoparticles to use them as a photocatalyst and an antimicrobial agent. Besides that, it studied improving properties of this nanomaterial to use in energy cells and sensors. The synthesis of ZnO nanoparticles in a biological way is accepted as an eco-friendly process. Since hazardous chemicals and high energy are not used, the biological method is called green synthesis. In the synthesis of ZnO nanoparticles via the green route, zinc nitrate or zinc acetate is the source of zinc salt added to biological extracts. These extracts can obtain from algae, plants, and bacteria. The reaction between the salt and extract occurs, then thermal treatment is applied to reach the nanoparticle.