M. Gullo

Assessment of insulated conductive cantilevers for biology and electrochemistry

This paper describes the characterization and application of electrically insulated conductive tips mounted on a cantilever for use in an atomic force microscope and operated in liquid. These multifunctional probes were microfabricated and designed for measurements on biological samples in buffer solution, but they can also be employed for electrochemical applications, in particular scanning electrochemical microscopy. The silicon nitride based cantilevers had a spring constant ≤0.1 N m-1 and a conductive tip, which was insulated except at the apex. The conductive core of the tip consisted of a metal, e.g. platinum silicide, and exhibited a typical radius of 15 nm. The mechanical and electrical characterization of the probe is presented and discussed. First measurements on the hexagonally packed intermediate layer of Deinococcus radiodurans demonstrated the possibility to adjust the image contrast by applying a voltage between a support and the conductive tip and to measure variations of less than 1 pA in faradaic current with a lateral resolution of 7.8 nm.

Development of Insulated Conductive Probes with Platinum Silicide Tips for Atomic Force Microscopy in Cell Biology

A microfabrication process of a multifunctional probe is introduced for atomic force microscopy and various electrochemical measurements on biological samples in buffer solution. The silicon nitride probes have a spring constant lower than 0.1 N/m and a conductive tip, which is tightly insulated except at the apex. The conductive core of the tip consists of PtxSi y and shows a typical radius of curvature of 15 nm. A simultaneous measurement of topography and electrical current on graphite in air was demonstrated.

Insulated Conductive Probes for in situ Experiments in Structural Biology

We report about the development of a multifunctional AFM probe, which allows to perform simultaneous measurements of topography and electrical properties of biological samples in a buffer solution. The quality of the AFM probes has been experimentally assessed by acquiring topography measurements of bacteriorhodopsin membranes in buffer solution and topographical and electrical current images of HOPG in air.

Atomic force microscopy for industry with the Akiyama-Probe sensor

For atomic force microscopy (AFM) to extend its usefulness into routine industry applications, its operation needs to be simplified. This paper shows how the novel Akiyama-Probe has been integrated in a commercial AFM to significantly simplify probe exchange.

Development of insulated conductive probes with platinum-silicide tips for AFM in cell biology

In this paper, we report about the development of this multifunctional AFM probe. This insulated conductive probes to measure the topography of biological membranes.

Fabrication of nano interdigitated electrodes

Thin-film Pt nano interdigitated electrodes realized by combining e-beam lithography and standard photolithography are presented. The resulting nano-IDAs have an active area of 76 μm × 100 μm, an electrode pitch of 785 nm and a gap of 250 nm. The initial results show that this technology is well adapted for the realization of sub-micrometer metallic structures.