Closed-loop ARS mode for scanning ion conductance microscopy with improved speed and stability for live cell imaging...

Area of Science:

• Nanotechnology
• Biophysics
• Microscopy

Background:

• Scanning Ion Conductance Microscopy (SICM) is vital for high-resolution, non-contact imaging of live biological specimens like cellular membranes.
• Approach-Retract-Scanning (ARS) mode in SICM allows rapid probing of delicate biological structures using a nano-pipette tip.
• Precise control of the nano-pipette tip position is crucial for optimal SICM performance.

Purpose of the Study:

• To develop and present a novel closed-loop control strategy for the ARS mode in SICM.
• To enhance operating speeds and stability during the tip approach phase.
• To improve the resolution and detail in imaging subtle biological features.

Main Methods:

• Implementation of a novel closed-loop control algorithm for ARS mode in SICM.
• Incorporation of a deceleration phase in the tip approach algorithm to prevent surface contact.
• Analysis of ion current and tip position data to validate performance.

Main Results:

• The new control strategy enables operating speeds of up to 250 μm s(-1).
• The deceleration phase significantly increases stability, minimizing unintended tip-sample contact.
• Achieved significantly improved, high-resolution imaging of subtle cellular features, including filamentous structures and membrane edges.

Conclusions:

• Optimization of tip approach speed substantially improves SICM imaging performance.
• The novel control strategy enhances SICM's utility as a versatile research tool for nanoscale biological studies.
• This advancement facilitates wider adoption of SICM in biological research.