Nanotechnology has emerged as a newer branch over the years and has evolved due to their applications in various sectors like industrial and biomedical activities. While the chemical synthesis of nanoparticles (NPs) has adverse effects on the environment and living beings, which led to the biological synthesis of NPs that has significantly helped reduce these effects, green synthesis of NPs has attributed with various sources that include plant extracts, animals, biological wastes, and microbes that are biologically safe, cost-effective, and eco-friendly. These microbes and plants have the ability to devour and accumulate these inorganic metal ions the niche and are able to synthesize NPs intracellularly or extracellularly. With advancement of nanotechnology and biology, it has helped use living entities such as bacteria, algae, yeasts, fungi, viruses, and plants. Finding their way in a range of unlimited applications in the medical and pharmaceutical industry that includes drug delivery or genes, detection of pathogens, tissue engineering, etc., the progressive green-synthesized NPs can be used as nanodiagnostics, as a means of biosensors to help efficiently detect animal pathogens and diseases.