Biosensing nanodevice to revolutionize health screenings

One day soon a biosensing nanodevice developed by Arizona State University researcher Wayne Frasch may eliminate long lines at airport security checkpoints and revolutionize health screenings for diseases like anthrax, cancer and antibiotic resistant Staphylococcus aureus (MRSA).

Even more incredible than the device itself, is that it is based on the world’s tiniest rotary motor: a biological engine measured on the order of molecules.

Frasch works with the enzyme F1-adenosine triphosphatase, better known as F1- ATPase. This enzyme, only 10 to 12 nanometers in diameter, has an axle that spins and produces torque. This tiny wonder is part of a complex of proteins key to creating energy in all living things, including photosynthesis in plants. F1-ATPase breaks down adenosine triphosphate (ATP) to adenosine diphospahte (ADP), releasing energy. Previous studies of its structure and characteristics have been the source of two Nobel Prizes awarded in 1979 and 1997.

It was through his own detailed study of the rotational mechanism of the F1-ATPase, which operates like a three-cylinder Mazda rotary motor, that Frasch conceived of a way to take this tiny biological powerhouse and couple it with science applications outside of the human body.

An article authored by Frasch and his colleagues in the ASU School of Life Sciences details the technology that would allow this. Their publication “Single-molecule detection of DNA via sequence-specific links between F1-ATPase motors and gold nanorod sensors” was recently published in the journal Lab on a Chip, and featured in the online journal Chemical Biology produced by the Royal Society of Chemistry.

What Frasch and his colleagues show is that the enzyme can be armed with an optical probe (gold nanorod) and manipulated to emit a signal when it detects a single molecule of target DNA. This is achieved by anchoring a quiescent F1-ATPase motor to a surface. A single strand of a reference biotinylated DNA molecule is then attached to its axle. The marker protein, biotin, on the DNA is known to bind specifically and tightly to the glycoprotein avidin, so an avidin-coated gold nanorod is then added. The avidin-nanorod attaches to the biotinylated DNA strand and forms a stable complex.