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“This new instrument was made to our specifications by NT-MDT,” says Vinci. “There is probably no other instrument in the world that is identical to our set-up. The NTEGRA actually contains no new part or component; it is exceptional because of the manner in which existing components are configured.”
The NTEGRA also has fluid cell capabilities to examine biological specimens, says Vinci.
“The NTEGRA is very complex. It is designed to be used for highly customized experiments that can last several weeks.“
What sets Lehigh’s NTEGRA apart from similar instruments, says Vinci, is its ability to simultaneously control the position of a specimen like a nanoparticle, the position of the AFM and the position of the stimulating laser.
Rotkin plans to use the NTEGRA to conduct studies of DNA-wrapped carbon nanotubes (CNTs) utilizing total internal reflection fluorescence (TIRF) in combination with AFM.
“TIRF is often used to look at live cells,” says Rotkin. “We want to look at CNTs, which are smaller than cells, as they sit inside a cell. CNTs are used in medical applications, so we need to find out whether they are harmful to cells.”
The NTEGRA, says Rotkin, is ideally suited to overcome one of the daunting challenges posed by CNTs – locating them on a substrate so they can be studied. It achieves this by combining TIRF and AFM.
“Our microscope can shine laser light at a large enough angle so that only nanoscale objects on top of the cover slip scatter light. If nothing is on the surface, the light is reflected and you see nothing.
If there’s an object on the surface, it scatters light and you see the object.
“The NTEGRA will enable us to investigate a surface with the AFM tip, find the nano-object, then examine it by focusing a light beam on the tip. Often you cannot see the object because it’s too small. The tip is like a big road sign saying ‘Here is your nanotube!’ We can run the TIRF experiment when we know where the object is and where the AFM tip is.
“In short, we will use AFM to locate the object and TIRF to probe the object optically.”
This three-way alignment – of a specimen, and the access to that specimen by both optical microscope and AFM tip – gives Lehigh’s NTEGRA its singular qualities, says Vinci.
“The simultaneous alignment of these three things is critical to the study of CNTs,” he says. “No other tool can do this as well as the new NTEGRA. Other manufacturers’ tools are excellent but they cannot match the NTEGRA’s capabilities.”