Scanning ion conductance

1 Combined Scanning Electrochemical Microscopy-Scanning Ion Conductance Microscopy 

The SICM was introduced by Hansma et al. in 1989 [111]. In general, the probe is typically a glass capillary pulled to a fine point, typically with a submicrometer capillary opening, filled with electrolyte solution and into which is placed an Ag/AgCl reference electrode. The probe sits in an 

However, SICM remains insensitive to the electrochemical properties of a surface, as the total ion flow is recorded thus the technique is not ion specific. SICM is also insensitive to neutral species in solution. By combining the power of SICM with SECM and integrating an electrode component into the SICM probe, it is possible to have a redox signal-independent measure of the surface topography, while recording local substrate electrochemical activity. This is in much the same way the AFM probe provides an independent measure of substrate structure in SECM-AFM. However unlike AFM, the SICM tip never makes contact with the surface so there is no risk of sample mechanical deformation. 

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Figure Bl.19.40. The scanning ion-conductance microscope (SICM) scans a micropipette over the contours of a surface, keepmg the electrical conductance tlirough the tip of the micropipette constant by adjusting the vertical height of the probe. (Taken from [211], figure 1.)...

Flansma P K, Drake B, Marti O, Gould SAC and Prater C B 1989 The scanning ion-conductance microscope Science 243 641... 

Other local probe techniques to be discussed, of an electrochemical nature, which rely on much of the same instrumental technology, are scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM). 

Scanning micropipette microscopy (SMM) Scanning micropipette molecule microscopy (SMMM) Scanning ion conductance microscopy (SICM)... 

Membrane imaging techniques based on the measurement of the local solution conductivity using scanning ion conductance microscopes have also... 

SECM associated with scanning ion conductance microscopy (SICM) requires a double tip, on one side of which is a conventional microdisc electrode and on the other side is a narrow pipette filled with electrolyte and an electrode that measures ionic conductance through the mouth of the pipette with respect to another electrode in the bulk solution. When the pipette mouth is within one pipette tip radius away from the sample surface, the conductance varies sufficiently to be used as a control signal to maintain the z-position of the tip during the scans, thereby affording constant-distance SECM operations [133,134]. This methodology is fast and apparently less-challenging to implement than shear force SECM, but it requires the fabrication of double-barrel tips in which one channel is left empty and the other is filled with a conventional microdisc. 

Optical microscopy Phase contrast microscopy Polarized light microscopy Scanning electron microscopy Scanning ion conductance microscope Scanning probe microscopy Scanning thermal profiler... 

Scanning ion-conductance microscopy (SICM) was initially developed to obtain topographical information on delicate and fragile samples, typically biological samples, immersed in liquid solution in a noncontact and noninvasive way [33]. SICM employs a hollow capillary as scanning probe instead of a microelectrode. 

Comstock DJ, Elam JW, Pellin MJ, Hersam MC (2010) Integrated ultramicroelectrode-nanopipet probe for concurrent scanning electrochemical microscopy and scanning ion conductance microscopy. Anal Chem 82(4) 1270-1276... 

O Connell MA, Wain AJ (2014) Mapping electroactivity at individual catalytic nanostructures using high-resolution scanning electrochemical-scanning ion conductance microcopy. Anal Chem 86(24) 12100-12107... 

SICM Scanning Ion Conductance Microscopy Surface Roughness Measurement... 

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