SOUTH AFRICA: Rhodes student in nano-tech breakthrough

Rhodes University PhD chemistry student Samuel Chigome has made a major breakthrough by creating tiny fibre filters that would allow scientists to make nano-technology devices that separate unwanted substances from liquid samples.

He managed this by using a fiber forming process called electrospinning, a technique that uses thousands of volts to turn 'big molecules', better known as polymers, into fibres that are 100 times smaller than the thickness of a human hair.

The 31-year-old, Zimbabwean-born Chigome said his innovation of an electrospun fibre-based solid phase extraction device acts as a 'smart filter' that traps a substance selectively and can be used to extract chemical constituents like steroids, pesticides and heavy metals from liquids.

"It is exciting to come out with such a breakthrough," Chigome told University World News.

"There were times when I felt like giving up but my supervisor, Professor Nelson Torto, always encouraged me. He really motivated me," Chigome enthused about the research that bore fruit after only a year.

He said the technology could be used in a wide range of areas interested in using polymer fibres for materials research. It could also be pertinent to areas such as water purification.

Chigome said one of the major concerns for the analysis of chemical constituents in an analytical chemistry laboratory was how to get the sample in a form that was suitable for accurate analysis with an analytical instrument.

"In the analysis of liquid samples, for example, biological samples like urine and plasma, a common problem is the presence of unwanted substances that can interfere with the accurate determination of the chemical constituents of interest," he said.

The simple-looking device also has other merits. Besides greatly reducing the overall time of analysis, his fibre filter allows for very small sample volumes to be used. This is a plus for researchers who can reduce the usage of environmentally unfriendly organic liquids.

Chigome said that his research had produced a simple, cost-effective and robust approach that left room for modifications to suit specific needs.

The work was published recently in the Royal Society of Chemistry's Journal of Analytical Methods.

In June, Chigome was invited to United States to present his innovation at an international conference where it was well received. Another spin-off was an invitation for him to write a review article for a sister publication, The Analyst, and to submit artwork for the cover of the Journal of Analytical Methods.

Buoyed by his achievement, Chigome paid tribute to the university: "I think, is a good reflection of the quality of research and research training coming out of this remote university," he said.