Controllable synthetic molecular channels: biomimetic ammonia switch

Area of Science:

• Computational chemistry and materials science
• Nanotechnology and molecular engineering

Background:

• Designing molecular pores with controllable and selective transport properties is crucial for applications in separation, sensing, and drug delivery.
• Existing molecular pore designs often lack precise mechanical control over their transport characteristics.

Purpose of the Study:

• To investigate the feasibility of designing mechanically controllable and selective molecular pores using molecular dynamics simulations.
• To explore two distinct model systems for creating tunable nanopores.

Main Methods:

• Employed molecular dynamics simulations coupled with iterative screening.
• Developed a model pore from stacked carbon nanocones with tunable pore size via rotation.
• Engineered a second model pore using carbon nanotubes and peptides, controlled by applied torque.

Main Results:

• The carbon nanocone model demonstrated mechanical control over nanopore size and liquid pentane flow rates by adjusting nanocone rotation.
• The carbon nanotube-peptide model showed reversible folding of peptides into different barrel structures upon torque application.
• Modification of internal residues in the peptide barrels resulted in a nanopore with significantly different hydrated ammonia (NH3) transmission rates in its two configurations.

Conclusions:

• Mechanically controllable and selective molecular pores can be designed using computational approaches.
• The proposed designs offer precise control over molecular transport, paving the way for advanced filtration and separation technologies.
• The developed nanopores exhibit tunable selectivity for specific molecules like hydrated ammonia.