Scientists develop self-constructing nanodevices for diagnosing diseases

Motor vehicles were created in the 19^th century as an efficient mode of transportation. As useful as they’ve proven to be, cars do not manufacture themselves, nor is it inexpensive to build one.  Scientists working at the Henderson lab at Iowa State University have successfully designed machines at the nanoscale that do just that — construct itself with regard to a difficult task at hand.

The scientists responsible for the development are Eric Henderson, a professor of genetics, development and cell biology at Iowa State University, and his former graduate student, Divita Mathur.

“These nanodevices have all these good qualities,” Mathur said. “[They] work a lot like normal-sized machines.”

The nanodevice is called OPTIMuS, and it works as a sensor to detect molecules at the nanoscale.

“In this case, these nanodevices can detect Ebola-mock DNA, which means that it can tell us if a sample has DNA sequences that are similar to the Ebola virus genome,” Mathur said.

Upon capturing a target molecule, OPTIMuS changes its shape. The shape change leads to a change in a fluorescent light signal received from the nanodevice. The fluorescence is then recorded by the lab. From there, the lab can analyze whether the target molecule is present or not.

“Like any machine, OPTIMuS takes input from the environment and releases a user-observable output,” Mathur said.

About 40 billion individual machines fit in a single drop of water, Professor Henderson said in a release, and the trick to creating the machines lies in understanding the rules that govern how DNA works.

OPTIMuS was constructed using DNA. DNA naturally lends itself programmable self-assembly, Mathur said.

When hundreds of DNA strands are heated and cooled, after being placed in a tube of water, millions of DNA nanostructures will form, making the construction of nanodevices inexpensive and simple.

“What you see here is a culmination of 5 years of research,” Mathur said. “It was only me and Eric who invested our time and energy on the work but we had some help for imaging the nanodevices from experts.”

Mathur said that her initial reason for joining Henderson’s lab was research, but after a few weeks in the lab, she found the environment to be extremely friendly, and she also enjoyed the independent aspect of the lab.

“Eric’s a great mentor for learning about science and research,” Mathur said. “If [students] run into any problems, Eric is always there to nudge them in the right direction.”

Mathur is a native of India, and she is currently a postdoctoral research fellow at the US Naval Research Laboratory in Washington, D.C. Mathur believes that she has a real passion for problem solving.

“I enjoy working with DNA to engineer nanoscale devices because it is a way of solving larger problems using a great nanosized building material,” Mathur said. “Doing research is a very deliberate and meticulous way of reaching solutions, so here I am!”

Mathur has five contributory published articles under her belt, as well as two first author publications, which includes the article describing her and Henderson’s nanodevice designs. The article can be found in the peer- reviewed journal “Scientific Reports.”

The next step for these nanodevices is to test them for detecting other target molecules, which will include real viral samples.

“We have achieved the first step in a process of engineering a fully functional diagnostic tool – we have demonstrated a working prototype,” Mathur said. “The end goal, truly, is to see this doing its magic as a point-of-care diagnostic tool for everybody’s use.”

Learn more: ISU scientists develop self-constructing nanodevices for diagnosing diseases