Potential of silica bodies (phytoliths) for nanotechnology

Many plant systems accumulate silica in solid form, creating intracellular or extracellular silica bodies (phytoliths) that are essential for growth, mechanical strength, rigidity, predator and fungal defence, stiffness and cooling. Silica is an inorganic amorphous oxide formed by polymerization processes within plants. There has been much research to gain new insights into its biochemistry and to mimic biosilicification. We review the background on plant silica bodies, silica uptake mechanisms and applications, and suggest possible ways of producing plant silica bodies with new functions. Silica bodies offer complementary properties to diatoms for nanotechnology, including large-scale availability from crop wastes, lack of organic impurities (in some), microencapsulation and microcrystalline quartz with possibly unique optical properties.