ABSTRACT
Pipettes are a versatile laboratory tool able to manipulate precise volumes of liquid and are prevalent in biology and chemistry. Exploiting nanopipettes as probes for scanning probe microscopy (SPM) has led to a straightforward route to high resolution, spatially resolved electrochemical measurements. In this chapter, the electrochemical nanopipette-based techniques including ITIES, scanning ion conductance microscopy (SICM), and electrochemical scanning droplet-contact methods are discussed. Characterization of micro/nanopipettes is critical to obtain quantitative electrochemical measurements. Pipette dimensions can be characterized electrochemically by placing the pipette filled with electrolyte solution and a back-inserted electrode into a bath of the same electrolyte solution, which houses a second electrode. Electrodes can also be characterized with a scanning electrochemical microscopy (SECM) approach curve. Micro/nanoscale electrochemistry requires electrodes suitable for the confined environment of a liquid filled pipette. Quasi-reference counter electrodes (QRCE) are back inserted into the barrel(s) of a filled pipette to control the potential between the pipette and external electrodes.
