Table 4.

Natural nanomaterials in living organisms and environments.

Occurrence	Nanostructures	Thickness/Diameter (nm)	Ref.
Human body	DNA	2–2.5 nm	[210]
	Enzymes	3–7 nm	[211]
	Antibodies	10–15 nm	[212]
	Bone Collagen fibrils	60–70 nm	[213]
	Mitochondria	1000 nm	[214]
Birds	Feathers (peacock)	<100 nm	[215]
	Feathers (scarlet macaw)	<100 nm	[216]
	Feathers (toucan)	<100 nm	[217]
	Feathers (blue jay)	<100 nm	[218]
Other vertebrates and insects	Panther chameleon skin	10–100 nm	[219]
	Poison dart frog skin	10–80 nm	[220]
	Moth eyes	~100 nm	[221]
	Butterfly wings	~100 nm	[222]
	Opal weevil (beetle)	2–10 nm (Photonic Nanocrystals)	[223]
Microorganisms	Magnetotactic bacteria	Bacteria produces magnetite nanocrystals ~50–100 nm	[224]
	Bacterial Cellulose	Bacteria produces celluloses nanofibers ~20–40 nm diameter	[225,226]
	Bacteria	0.6–5000 nm	[227]
	Virus	50–150 nm	[228]
	Fungi	Setae with a spatula of 50–100 nm in size	[229]
Aquatic ecosystems	Blue-rayed limpet	Shell containing 50–100 nm particles	[230]
	Clownfish	10–100 nm	[231]
	Blue-ringed octopus	10–100 nm	[232]
	Lobster eggs	500–600 nm	[233]
Soil	Clays	3.5–5 nm	[234]
	Manganese hydrous oxide nano-minerals	3–5 nm	[235]
	Ferric iron hematite crystals	5–6 nm	[235]
	Red latosol topsoil	200 nm	[236]
Space	Lunar dust	500 nm	[237]
	Mars dust particles	50–200	[238]
	Mars soil	30–100 nm	[239]