Research group Kranz

Multifunctional Scanning Probes

In recent years, we have pioneered the integration of scanning electrochemical microscopy (SECM) functionality into atomic force microscopy (AFM) tips with an electrode area recessed from the apex of the AFM tip. With this approach, tip-integrated micro- and nanoelectrodes may be operated in an electrochemical imaging mode while simultaneously recording high resolution topographical information via AFM. Furthermore, appropriate modification of the electrode surface enables the integration of a wide variety of amperometric or potentiometric electrochemical sensing principles, as the AFM tip ensures a constant distance between the integrated electrode and the sample surface. Multifunctional AFM probes with integrated electrochemical sensing capabilities provide a unique tool for the inherent correlation of structural information with (electro)chemical surface activity at high lateral and temporal resolution. Microfabrication techniques in combination with focused ion beam (FIB) milling or batch fabrication at a wafer level enable the reproducible integration of ultramicro- and nanoelectrodes into AFM tips with a tailorable geometry (e.g., ring, disk, etc.), and from an extensive selection of electrode materials/properties (e.g., gold, platinum, iridium, antimony, etc.).

Current research focuses on the application of advanced multifunctional scanning probes in cell biology providing (bio)chemical information correlated in space and time with changes of the topography at live specimen such as e.g., cells, cell ensembles, tissues, etc..

Conventional SECM using microelectrodes is currently applied in research projects centering on electrochemical imaging applications using thin-film amalgam (Au/Hg) electrodes for studies related to biocorrosion processes, and on imaging applications using dual-electrode amperometric biosensor assemblies for studying molecular signals at cell surfaces.

In extension of these concepts we have recently demonstrated the combination of various scanning probe techniques with mid-infrared spectroscopy, thereby providing a profound basis for the development of next-generation multifunctional analytical platforms.

Current Projects

  • Combined atomic force scanning electrochemical microscopy (AFM-SECM) with bifunctional probes
  • Bifunctional AFM-SECM probes with tip-integrated amperometric micro- and nanobiosensors
  • Bifunctional AFM-SECM probes with tip-integrated potentiometric micro- and nanosensors
  • AFM-SECM for functional life cell imaging at lung epithelial cells
  • SECM with functionalized (ultra)microelectrodes