Nanoparticles (NPs) are materials with a size scale of 100 nm or less. They are produced using a combination of chemical and physical techniques, and frequently include the use of hazardous substances. These hazardous substances are difficult to remove from nanoparticle surfaces, making them bioincompatible and limiting their application as biomedical nanoparticles. Nanoparticles can currently be synthesized biologically using methods based on green chemistry. The fusion of nanotechnology and biology has given rise to a new field called nanobiotechnology, which aims to harness biological entities such as actinomycetes, algae, bacteria, fungi, viruses, yeast, and plants in a number of physicochemical, biochemical, and biophysical processes. Plant extracts have been used in biological applications because they are a rich source of phytomolecules and because their capping and reducing capabilities have been used in the production of metal and metal oxide NPs. The biosynthesized NPs have not only been examined for their antibacterial, antifungal, antioxidant, anticancer, and biocompatibility properties but also for their morphology using a number of analytical techniques. This approach, which is affordable and environmentally friendly, could substitute traditional chemical and physical methods for biomedical applications.