Before the dream of making gold nuggets goes too far, the new research is at the nano-scale and involves the creation of gold nanowires. These are over 1000 times smaller than a human hair. The process involves the use of a device invented by Professor Bret Flanders and Govind Paneru.
The process has been developed by Kansas State University scientists and the intended application is the biomedical field, to create electrodes for devices used in organ transplant procedures. The electrodes are used to manipulate and sense characteristics of individual cells.
The nanowires are produced electrochemically. This involves accumulating particles from solution into a new wire. The process is similar to the way a snowflake is formed. With a snowflake, water vapor molecules in the air condense onto the surface of pollen or dust, eventually forming the classic ‘snowflake’ crystalline structure. With the gold nanowires, gold atoms condense onto a sharpened tip. The sharpening is, somewhat surprisingly, through a sewing machine. The sewing machine works by oscillating a microelectrode up and down in a beaker of potassium chloride solution. This prevents that nanowire from dissolving.
Discussing the importance with Controlled Environments magazine, Professor Flanders said: “Conventional surgical tools, including electrodes that are implanted in people’s tissue, are unfavorably large on the cellular level.”
He added: “Working at the individual cellular level is of increasing importance in areas such as neurosurgery. Potentially, this sleek device, made from gold nanowires, could get in close and do the job.”
The effectiveness of the nanowires is based on their size. Being smaller than a human cell means that the wires can pierce a biological cell to stimulate the cell membrane. The wires can also be used to investigate a cell’s interior.
The research has been published in the journal Applied Physics Letters and Nanotechnology. The paper is headed “Directed growth of single-crystal indium wires.”
