Characterization of Membrane Patch-Ion Channel Probes for Scanning Ion Conductance Microscopy

Area of Science:

• Nanotechnology
• Biophysics
• Chemical Sensing

Background:

• Scanning ion conductance microscopy (SICM) offers high-resolution imaging.
• Ion channel probes are crucial for studying biological transport.
• Combining these technologies presents new opportunities for chemical sensing.

Purpose of the Study:

• To integrate dual-barrel membrane patch-ion channel probes (MP-ICPs) with SICM.
• To investigate the fundamental principles governing this combined system.
• To demonstrate site-specific molecular/ionic flux sensing at the single-ion-channel level.

Main Methods:

• Construction of MP-ICPs with various ion channels (TRPV1, BK channels).
• Measurement of single ion channel activity using the MP-ICP platform.
• Systematic study of the interplay between SICM and ICP barrels, including electrical potential effects.

Main Results:

• MP-ICPs demonstrated generalizability across different ion channel types.
• Single ion channel activity measurements were successfully performed.
• The SICM barrel potential influenced ion channels gated by charged ligands, enhancing activity when polarity was opposite to the ligand charge.
• Site-specific molecular/ionic flux sensing was achieved, enabling quantification of local concentrations.

Conclusions:

• The MP-ICP-SICM platform provides a revolutionary approach to spatially resolved chemical sensing.
• The system allows for precise control and measurement of ion channel activity.
• This technology can quantify local molecular and ionic concentrations at the single-ion-channel level.