A Cantilevered Glass Conductance    & Patch Clamping Probe Diagrammatic Representation of a Nanonics Glass OptiProbe - Optically Friendly AFM Probes with Conductance Capabilities Nanonics has developed solutions to both the probe and the scanning problems of standard AFM Systems. In the images above show the solution to the problem of the probe obscuring the optical axis. This solution uses cantilevered transparent glass probes that can either be made of optical fibers or nanopipettes .  All such probes have their tips exposed to the optical axis and the axis is kept completely free for a variety of optical microscopic protocols that require a free optical axis. Nanopipettes can be used either in a cantilevered or in a straight configuration and are ideal for ion conductance microscopy.

Nanonics Systems for Analyzing Membranes & Other Porous Materials

Nanonics systems in addition to their standard AFM capabilities have unique capabilities in terms of the non-destructive analysis and the correlation of the structure and porosity of porous materials such as biological membranes. These Capabilities Arise from:

The ability to perform AFM controlled conductance microscopy with Nanonics' extensive experience in nanopipette SPM technology The ability to perform confocal imaging with the same platform as the AFM and conductance microscopy

AFM Controlled Conductance Microscopy

Nanonics SPM systems are unique in that they can use glass cantilevers.  One such cantilever of great importance for investigating Nanoporous materials non-destructively is the cantilevered nanopipette that can perform at the same time atomic force microscopy even in intermittant contact mode with conductance of ions through the pores of the sample.  In the figure above the tip of such a nanopipette is shown investigating a pore in a sample.  In the cantilevered nanopipette is inserted an electrode on one side of the porous sample and with a counter electrode in the solution.   Such a set-up is used to provide for measuring conductance of pores and thus porosity.  The porosity is measured by the conductance and the structure with the same probe acting as an AFM.

From Biophysical Journal 71, 2155 (1996) The AFM image with the cantilevered nanopipette in A of a nucleopore membrane and the conductance microscopic image in B.  In the top circle in A we see a very deep pore as shown by the white region but in this region in the conductance image there is very little conductance showing that the porosity of the pore in this region is very low independent of the structure.  This should be compared to the bottom circles in both images.  In A the bottom circle shows pores with much less depth using AFM but the porosity shown through conductance is very high.     The Cell Membrane an Active Porous Medium

The ultimate use of Nanonics systems for AFM controlled patch clamping is still to be implemented.  AFM coupled with patch clamping will allow for high resolution conductance and topographic analysis of the cell membrane before either implementing a loose or other patch clamping technology.  They will also allow for monitoring of cell membrane movement with ionic conductance.  The conductance measurements done so far with the system portend great success in this area.