As carbon nanotubes (CNTs) are excellent water transporters, the researchers use all-atom molecular dynamics simulations to study the translocation of charged NPs through a fluidic CNT. A series of simulations are conducted for NPs with different polymer length, polymer number, charge amount and charge position. With the increase in polymer length, the NP flux decreases as a whole due to the increase in NP size. The negatively charged NP translocation fails at the smallest polymer length because of the strong binding of Na+.

Increasing the flux

Surprisingly, the NP flux exhibits a maximum with the increase of polymer number or charge amount, which is co-determined by the NP net charge and size. Owing to the NP-membrane adsorption and NP-ion binding, the NP flux decreases with the decrease of charge position.

Nanoparticle delivery applications

These results reveal the important role of grafted polymers in the NP translocation and may have implications in the design of highly efficient NP delivery. As in recent experiments, single NP translocation and detection has been achieved technically, so the researchers hope that their results can guide experimental researchers in the near future.

More information can be found in the journal Nanotechnology 25 185703.

Further reading

Using solid-state nanopores to examine proteins (Apr 2014)
Ion age transport: Developing devices beyond electronics (Mar 2014)
Nanopores form more quickly through FIB boiling (Jan 2014)