Green nanotechnology – A new hope for medical biology

•Green nanotechnology has drawn on the field on green chemistry.•Biosynthesis of nanoparticles is a kind of bottom up approach with reduction/oxidation.•Efficient control of MNPs size and shape, critical to optimize MNP-based devices.•It aims to reduce hazardous waste generation and safer applications.

The development of eco-friendly technologies in material synthesis is of considerable importance to expand their biological applications. Nowadays, a variety of green nanoparticles with well-defined chemical composition, size, and morphology have been synthesized by different methods and their applications in many cutting-edge technological areas have been explored. This review highlights the classification of nanoparticles giving special emphasis on biosynthesis of metal nanoparticle by viable organisms. It also focuses on the applications of these biosynthesized nanoparticles in a wide spectrum of potential areas of medical biology including catalysis, targeted drug delivery, cancer treatment, antibacterial agents and as biosensors.