Nanoparticles secreted from ivy rootlets for surface climbing.

Using atomic force microscopy, we observed ivy secretes nanoparticles through adhering disks of the ivy aerial rootlets which allow the plant to affix to a surface. We analyzed the organic composition of the secretions using high-performance liquid chromatography/mass spectrometry and were able to determine the formula of 19 compounds. This study suggests that the nanoparticles play a direct and important role for ivy surface "climbing". Weak adhesion and hydrogen bonding seem to be the forces for the climbing mechanism. This ivy secretion mechanism may inspire new methods for synthesizing nanoparticles biologically or new approaches to adhesion mechanisms for engineering applications.