  The integration of biosensing platforms with drug delivery systems has led to
effective treatment strategies for biomedical applications. With the emergency
of nanotechnology, the manipulation of materials in the nanometer, these
biosensing and drug delivery systems have been tremendously improved due to the
exceptional properties exhibited by these materials. The conventional
approaches used to synthesize the nanomaterials including physical and chemical
methods involve the usage of harsh chemicals and hazardous reaction conditions
and hence posing a threat to health and the environment. This problem is solved
by the biological methods that involve green nanotechnology which integrates
green chemistry and engineering principles to formulate harmless and
eco-friendly nanomaterials to fight the complications affecting human health
and the environment. These biological methods use phytochemicals found in
plants and plants parts as well as microorganisms for the bioreduction of metal
ions to their corresponding nanomaterials. The plants and the microorganisms
are readily available, cost-efficient, and have biocompatibility hence offering
sustainable synthetic methods for nanomaterials. This review will therefore
focus on the plant-mediated and microbe-mediated green synthesis of different
nanomaterials, the mechanisms of these synthetic methods, the application of
the green synthesized nanomaterials in biosensing and drug delivery as well as
the challenges of the synthetic methods.
