Light-powered nano-submarines could deliver medicine inside the body
by Julie M. Rodriguez
A team from Rice University has created a single-molecule, submersible machine that could one day be used to target medications toward specific parts of the body. The Unimolecular Submersible Nanomachines (USNs) are made of 244 individual atoms that are bound together to create a microscopic device powered by ultraviolet light and can be tracked using lasers.
The device is powered by a tail-like propeller that moves 18 nanometers per cycle, at more than a million RPM. That’s the equivalent of an inch per second. While that may not seem especially fast in human terms, Rice chemist James Tour claims the USNs “are the fastest-moving molecules ever seen in solution.”
The speed is more than adequate to allow the medical devices to travel through the human body, given that a full minute of travel can take the devices five feet. Researchers have also equipped the USNs with a tracking device — when excited by a laser, the submersibles contain a pontoon that glows red, making it easy to track their progress.
While the technology is promising, the nanosubs aren’t yet ready for practical applications. For one thing, researchers still haven’t created a way to steer the tiny machines in a particular direction. However, the team is hopeful that such a thing can be done. The lead author of the study, Rice graduate student Victor García-López stated, “There’s a path forward. This is the first step, and we’ve proven the concept. Now we need to explore opportunities and potential applications.”
The full study was published in the journal Nano Letters.