Figure 1: Bioprobe with a fully integrated sharp-tipped hollow SiO2 nanoneedle and fluidic microchannel embedded into a Si cantilever beam structure.
The bioprobe enables both the quantitative introduction of the desired biomolecules (DNA, proteins, etc.) into living cells and extraction of an extremely small number of biomolecules or cellular components expressed inside the cells as well as a variety of functions of conventional AFM functions.
The electrically insulating and optically transparent properties of the hollow structure of the SiO2 nanoneedle provides other useful functions including (1) scanning ion conductance microscopy (SICM) for non-damaging imaging of biological cells; (2) scanning near-field optical microscopy (SNOM) for high-resolution optical imaging; and (3) surface enhanced Raman scattering (SERS) spectroscopy for characterizing molecular interactions in the biological cell.
Figure 2: Atomic force microscope (AFM) phase images of HeLa cells in a culture medium and introduction of a fluorescent dye into a living HeLa cell by penetration of its cell membrane with the nanoneedle tip of bioprobe.
Importantly, bioprobe has the potential to enable simultaneous imaging of multiple signals from single living cells. The researchers are confident that this approach will provide a method for correlation analysis of cellular functions with high spatial and temporal resolution for the development of a viable strategy for improving health and quality of life.