Unpredictable Ion Flow Behavior

Despite their significance in research and technology, biological nanopores often behave unpredictably. Scientists still lack a full understanding of how ions move through these tiny channels—or why that movement can abruptly halt.

Figure 1. Minute Nanopores Display Surprising Neural-Style Learning.

Two persistent puzzles have been especially hard to unravel: rectification and gating. Rectification refers to changes in ion flow based on the polarity (positive or negative) of the applied voltage, while gating describes sudden drops in ion flow. These effects, especially gating, can disrupt sensing technologies and have long remained only partially understood. Figure 1 shows Minute Nanopores Display Surprising Neural-Style Learning.

Pinpointing the Forces Behind Rectification and Gating

A research team led by Matteo Dal Peraro and Aleksandra Radenovic at EPFL has now shed light on the physical origins of these long-standing mysteries. Using a blend of experiments, computational simulations, and theoretical analysis, they discovered that both rectification and gating stem from the electrical charges inside the nanopore and the way these charges interact with passing ions.

Probing Charge Patterns with Engineered Nanopores

The researchers focused on aerolysin, a bacterial nanopore widely used in sensing applications. By modifying the charged amino acids lining the pore’s interior, they engineered 26 distinct versions—each with a unique charge distribution. They then measured ion flow through each variant under different experimental conditions.

To observe how rectification and gating unfold over time, the team applied alternating voltage signals. This allowed them to separate rapid rectification responses from the slower gating events. Finally, they used biophysical models to interpret the behavior and pinpoint the mechanisms driving these effects.

Insights Into Ion Flow and Structural Stability

The study revealed that rectification arises from how the nanopore’s internal charge layout influences ion movement—making it easier for ions to travel in one direction than the other. Gating, however, comes from a different mechanism: when a strong stream of ions generates a charge imbalance, the pore becomes structurally unstable. Part of the pore briefly collapses, blocking ion flow until the structure returns to its original state.

Both rectification and gating depend on the amount and precise placement of charged residues inside the pore, as well as whether those charges are positive or negative. By altering the “sign” of these charges, the researchers could shift when and how gating occurred. They also found that increasing the pore’s rigidity eliminates gating altogether, showing that structural flexibility is crucial for this behavior.

Toward Programmable and Adaptive Nanopores

These discoveries offer a blueprint for engineering biological nanopores optimized for specific applications. Designers can now tune pores to avoid gating in sensing technologies—or intentionally leverage gating for bio-inspired computing. In one example, the team engineered a nanopore that mimics synaptic plasticity, effectively “learning” from repeated voltage pulses like a neural synapse. This adaptive capability hints at future ion-based processors that could use nanopores as fundamental computing elements.

Source: SciTECHDaily

Cite this article:

Priyadharshini S (2025), Scientists Reveal How Minute Nanopores Mimic Brain-Like Learnin, AnaTechMaz, pp. 439