Gated Molecular Transport in Highly Ordered Heterogeneous Nanochannel Array Electrode

Area of Science:

• * Nanotechnology
• * Materials Science
• * Electrochemistry

Background:

• * Protein channels facilitate selective ion transport via hydrophobic and charged regions.
• * Understanding artificial nanochannel transport is crucial for biological mimicry.

Purpose of the Study:

• * To engineer heterogeneous silica nanochannels (HSNs) with tunable ion transport properties.
• * To investigate the combined effects of hydrophobic and electrostatic forces on ion selectivity.

Main Methods:

• * Fabricating HSNs by coating charged silica nanochannels with a polydimethylsiloxane (PDMS) layer.
• * Employing voltammetric studies to analyze ion transport characteristics.
• * Modulating transport by adjusting PDMS thickness, salt concentration, pH, and applied voltage.

Main Results:

• * HSNs exhibit dual control over ion transport through hydrophobic rejection (PDMS) and electrostatic forces (silica).
• * Anionic transport is prohibited due to combined repulsion.
• * Cationic transport is enabled when electrostatic attraction overcomes hydrophobic rejection.
• * HSNs can be switched from an ion-impermeable (OFF) to a cation-selective (ON) state.

Conclusions:

• * HSNs offer a versatile platform for controlling ion transport at the nanoscale.
• * The interplay between hydrophobic and electrostatic forces is key to achieving selective ion permeability.
• * This work provides insights into designing advanced materials for ion separation and sensing applications.