Scientists use carbon nanotube forest to capture hard-to-detect molecules
Researchers atMIT have developed a new method for detecting elusive molecules,using an array or "forest" of carbon nanotubes. The technique canbe finely tuned, allowing it to be used for the capture of very smallparticles, including those of certain viruses.
Carbon nanotubes have been the subject of many studies, with researchersworking to harness their potential for various purposes, from small sensors that can detect spoiled meat, to anti-icing coatings for aircraft. Now, an MIT research team has turned the material towards capturing tiny bioparticles.
The new methodmakes use of carbon nanotubes which have been manipulated to stand on their ends,creating an array that the team describes as being "like trees in aforest." Taking advantage of the fact that the material is 99percent porous, the arrangement allows for the creation of athree-dimensional, highly permeable array within a microfluidic device.
Theresearchers coated the vertically-arranged nanotubes in successivelylayers of alternately charged polymer solutions, giving the arraythe ability to trap certain particles. This ability can be tuned bychemically treating the nanotubes, allowing select molecules to becaptured.
Duringtesting, the team treated the nanotubes with antibodies that bind toprostate specific antigen (PSA), before pumping a solution containingsmall amounts of PSA through the array. The coating was found to trap 40 percent more antigens than a non-coated version of thearray, with molecules captured throughout the structure rather thanjust on the outer surface, as is common with typical microfluidicsystems
Thanks to its highly versatile nature, the nanotubearray could end up being an extremely useful tool. Inparticular, it could prove effective at targeting tiny biomarkerscalled exosomes, which have a width of less than 100 nanometers.
"There aresmaller bioparticles that contain a very rich amount of informationthat we don't currently have the ability to access in point-of-care[medical testing] devices like microfluidic chips," says MIT'sBrian Wardle. "Carbon nanotube arrays could actually be a platformthat could target that size of bioparticle."
The findingsof the research were published in the Journal of Microengineering and Nanotechnology.