AFM/EC Nano Probing of Single Cells and Organelles

We have developed a single cell/organelle platform to provide experimental access and control over the electrochemical reactions involved in metabolic pathways of biological microorganisms. As sensing elements we have been using unique needle shaped Atomic Force Microscope (AFM) probes with integrated single or dual electrochemical (EC) nano electrodes. The probe system is designed for local probing of the cytosolic cell environment and cell organelles using amperometric, potentiometric and impedance spectroscopic methods. The sharpness of the probe tip is less than 30nm and allows for a reliable penetration of cell membranes. Reliable immobilization of living single cells and full control of the chemical micro environment close to the single cell has been achieved by introducing a open micro channel systems. Furthermore, this probing set up significantly reduces parasitic electrical capacitances and allows for current detection in sub pico-ampere regime at high signal band widths. Fabrication strategies of the AFM/EC nano probe system as well as open channel micro fluidic systems for single cell/organelle probing will be introduced. Further, the results of using this platform to explore in situ energy conversion reactions in single algae cells and chloroplast and their potential for bio energy sources will be presented and discussed.