Nanotech Scientists Make Football Molecule With Water Core

With new technique developed by Columbia Engineering researchers managed to encapsulate a single water molecule inside a football-shaped carbon (C₆₀) molecular structure.

This trick enabled the possibilty to drive motion of the so-called "big" nonpolar ball through the encapsulated "small" polar H2O molecule, a controlling transport mechanism in a nanochannel under an external electric field. The researchers said they expect this method will lead to an array of new applications, including effective ways to control drug delivery and to assemble C60-based functional 3D structures at the nanoscale level, as well as expanding our understanding of single molecule properties.

The key discovery that the resulting structure responds in a surprising way to an electric field was made using computer modeling: the whole structure can be driven in either direction through a narrow channel, with adjustable transport velocity

The spherical, hollow molecular structure is made of 60 carbon atoms that are connected in the exact same pattern as the classical football, and is known as fullerenes (also Buckminsterfullerenes or Buckyball). They have a diameter of about 1 nm - 6,000-8,000 times smaller than a red blood cell.

Because of their relative non-toxicity to the human body, their hydrophobic core (which keeps water-soluble substances trapped), and  their covalent nonpolar bonds (don't interact electrically with other molecules), fullerenes are a perfect container for delivering drug molecules, explains Xi Chen, associate professor of earth and environmental engineering, who led the research. They could also have other nanotech and biotech applications.

Since the discovery of C60 in the 1980s, scientists have been trying to solve the challenge of controlling a single C₆₀ molecule. Several mechanical strategies involving AFM (atomic force microscopy) have been developed, but these are costly and time-intensive. The ability to drive a single C₆₀ through a simple external force field, such as an electrical or magnetic field, would be a major step forward.

Study:

Baoxing Xu, Xi Chen, Electrical-Driven Transport of Endohedral Fullerene Encapsulating a Single Water Molecule, Physical Review Letters, 2013, DOI: 10.1103/PhysRevLett.110.156103