Fabrication of bioprobe integrated with hollow nanoneedle for cellular function analysis

In order to realize cellular function analysis in a single living cell, we have been developing a newly designed probe for atomic force microscope (AFM), named “bioprobe”, which is integrated with a hollow silicon dioxide (SiO₂) nanoneedle. The probe will be capable not only of performing AFM measurements but also of introducing desired biomolecules (DNA, proteins, etc.) into living cells and extracting biomolecules expressed in the cells. In this paper, we demonstrated the ability of the fabricated bioprobe to capture AFM images of living HeLa cells under near-physiological conditions. Moreover, the sharp-tipped SiO₂ nanoneedle can be inserted into the cells without significant cell damage. In order to examine the possibility of liquid delivery, water ejection tests were also carried out. As a result, an extremely small amount of water can be ejected through a nanoneedle.