By mimicking the structure of the silk moth's antenna, University of Michigan researchers led the development of a better nanopore. Nanopores are essentially holes drilled in a silicon chip and are miniscule measurement devices that enable the study of single molecules or proteins that could advance understanding of a class of neurodegenerative diseases that includes Alzheimer's, Parkinson's, and Huntington's diseases. Nanopores could also be used to detect biological warfare agents. The team engineered an oily coating that traps and smoothly transports molecules of interest through nanopores. The coating also allows researchers to adjust the size of the pore with close-to-atomic precision.
Inspired by the olfactory sensilla of insect antennae, the researchers showed that "coating nanopores with a fluid lipid bilayer tailors their surface chemistry and allows fine-tuning and dynamic variation of pore diameters in subnanometre increments...Lipid coatings also prevented pores from clogging, eliminated non-specific binding and enabled the translocation of amyloid-beta (Aβ) oligomers and fibrils." Amyloid-beta peptides that are thought to coagulate into fibers that affect the brain in Alzheimer's patients.
Insects detect pheromones by moving odorant molecules through lipid-coated nanopores (diameter, 6–65 nm) that span their exoskeleton. These lipid coatings are thought to participate in the capture, pre-concentration and subsequent movement of odorants to specific receptors on olfactory neurons in the antennae of insects. Inspired by this design, the researchers explored whether coating synthetic nanopores of comparable diameters with fluid lipid bilayers could provide benefits for nanopore-based, resistive pulse sensing of single proteins. This fluid type of coating would be an improvement over existing coatings that were fixed to the walls of the nanopores.Sources: Yusko EC; Johnson JM; Majd S; Prangkio P; Rollings RC; Li J; Yang J; Mayer M. 2011. Controlling protein translocation through nanopores with bio-inspired fluid walls. Nature Nanotechnology 6(4):253-260.Moore NC. 2011. Silk moth's antenna inspires new nanotech tool with applications in Alzheimer's research. EurekaAlert February 28, 2011.
"Synthetic nanopores have been used to study individual biomolecules in high throughput, but their performance as sensors does not match that of biological ion channels. Challenges include control of nanopore diameters and surface chemistry, modification of the translocation times of single-molecule analytes through nanopores, and prevention of non-specific interactions with pore walls."Edit Summary