Signal transmission, conversion and multiplication by polar molecules confined in nanochannels

Abstract

The mechanism of signal transmission, conversion and multiplication at molecular level has been of great interest lately, due to its wide applications in nanoscience and nanotechnology. The interferences between authentic signals and thermal noises at the nanoscale make it difficult for molecular signal transduction. Here we review some of our recent progress on the signal transduction mediated by water and other polar molecules confined in nanochannels, such as Y-shaped carbon nanotubes. We also explore possible future directions in this emerging field. These studies on molecular signal conduction might have significance in future designs and applications of nanoscale electronic devices, and might also provide useful insights for a better understanding of signal conduction in both physical and biological systems.

Small Molecules and Peptides Inside Carbon Nanotubes: Impact of Nanoscale Confinement

“…15(b) and (e)], which was much more stable than single strand in bulk water. Our recently theoretical investigation has shown that the hydrophobic effect plays a significant role in protein self-assembly in water, in which the "dewetting transition" can be induced by the hydrophobic interaction between two strands in both amyloid-β peptides (KLVFFAE) and hIAPP [22][23][24][25][26][27] peptides (NFGAIL) [107,108]. Our simulations confirm that beta-strand conformation can be stabilized in hydrophobic environment, which could further promote the formation of protofilaments and form amyloid fibrils.…”

“…The structure of this chapter will be organized as following. First, we show that water molecules confined within a Y-shaped CNT can realize the molecular signal conversion and multiplication, due to the surprisingly strong dipole-induced orientation ordering of confined water wires [25]. Second, we find a striking phenomen that urea can induce the drying of CNTs and result in single-file urea wires.…”

“…Our previous reports [21,25] have demonstrated water wires can mediate the signal conversion and multiplication because of their ordered 1D structure and collective flipping behavior. However, the very small size of the water and fast flipping of water wire make the experimental realization very difficult [25].…”

“…Our previous reports [21,25] have demonstrated water wires can mediate the signal conversion and multiplication because of their ordered 1D structure and collective flipping behavior. However, the very small size of the water and fast flipping of water wire make the experimental realization very difficult [25]. Urea wire has similar ordered 1D structure and flipping behavior as water wire but has a lower flipping frequency and a high molecular polarity which can facilitate the signal detection in practice (urea wire has longer response time [21] to switch its dipole orientation un-der the influence of a change in charge signal).…”

Molecular dynamics studies on the influences of a gradient electric field on the water chain in a peptide nanotube

“…[4][5][6][7][8]. Molecular dynamics (MD) simulations have explored the effects of an electric field on nanochannel transportation characteristics, where an electric field can be achieved by assigning charges near a nanochannel [9][10][11][12][13][14][15], adding ions to the water phases on both sides of a nanotube [16][17][18], or directly using MD software such as NAMD [8,19,20], GROMACS, etc. [21][22][23].…”