Barriers t o permeation of ions through nanotubes

Ion channels are pore-forming proteins that help th e establish ment and co ntrol the v oltage gradient across the plasma membrane of cells by allowing the flow of ions down their elect rochemical gradient. T hey are pre sent in the membranes that surround all biol ogical cells. They are r esponsible f or processes such as the effluence o f nerve impulses and m uscle contraction. Due to the comparable size of CNT to a biological ion channe l [۱], a CNT has been considered to have great potential for applica tions in biological nanosystems. B NNTs can b e also find interesting applications in biologic al nanoflui dic systems, because of their exciting properti es. The per meation of ions across membranes enclosing living cells is an essential proced ure that controls the el ectrical pro perties of th e cells, su ch as, the a ction poten tial generation in ner ves and muscles [۲]. T he cell membrane, however, is almost impassable to io ns. Thus, an ion channe l is needed to allow th e transfer of ions in and out of the cell through the mem branes. Ea ch ion channel can be particular for a single ion or conduct a few o r several i ons. During the past decade, severa l nanotubes or nanocha nnels have been proposed as artificial ion channels to mimic t he selectivity properties of biological ion channels.

کلیدواژه ها:

Molecular Dynamics simula tions ، nanotube ، preferential perme ation.