Scanning ion conductance microscopy (SICM) is becoming a multifunctional tool for probing surfaces and interfaces. This thesis extends the capabilities of SICM, exploiting the ability of nanopipettes to deliver ionic redox species to a substrate, with a high degree of spatial and temporal precision. Two methodologies for nanopipette delivery have been developed: (i) pulsed-potential SICM, i.e. the ionic redox species can be held in the nanopipette or pulse-delivered to a defined region of a substrate positioned beneath the nanopipette through control of the SICM bias between a quasi-reference counter electrode (QRCE) in the nanopipette and a similar electrode in bulk; and (ii) differential-concentration (ΔC-) SICM, i.e. the ionic species can be delivered from the nanopipette to a surface through a small SICM bias between the two QRCEs, purely due to different concentrations (compositions) of solutions employed in the nanopipette and bulk.

In the single-channel setup, SICM with pulsed-potential nanopipette delivery allows the synchronous mapping of electrode reactivity, surface charge and surface topography in a single measurement by analysis of the tip and substrate current data. This regime has been further applied to mimic the exocytotic release of neurotransmitters to investigate the spatiotemporal heterogeneity in the electrochemical behavior of carbon fiber UMEs. When integrating pulsed-potential nanopipette delivery into SICM-SECM, information about the electrochemical reaction can be obtained from the current signal at the SECM probe as well as from the substrate, in addition to the correlated surface topography obtained synchronously. With ΔC-SICM, information about the local electrochemical reaction can be obtained purely from the nanopipette response.

The studies outlined in this thesis, and the accompanying finite element method (FEM) modeling, greatly improve understanding of mass transport in SICM, and, in particular, provide a new platform for electrode mapping. This thesis highlights the versatility of SICM, with considerable applications envisaged, spanning electrochemistry, catalysis and cell biology.