Tiny New Lab-On-A-Chip Design May Improve Handheld Diagnostics
By Joel Lindsey
Researchers at the University of New South Wales (UNSW) in Australia have developed a novel approach to fabricating miniaturized lab-on-a-chip devices by using a class of non-volatile ionic liquids as solvents. The team’s findings could impact the design of future medical diagnostics, according to a report published in the journal Nature Communications.
One challenge that has continually plagued the development of effective lab-on-a-chip devices — which facilitate chemical reactions on a miniature scale for analytical purposes — has been finding a solvent that doesn’t evaporate too quickly. Evaporation is problematic because it “can affect the concentration of substances and disrupt the reaction,” according to a press release issued recently by UNSW.
Past attempts to solve this problem have focused on creating reservoirs or channels in the microchip to store solvents. However, the researchers involved with this project may have found a more effective alternative.
“We use a class of ‘green’ solvents called ionic liquids, which are salts that are liquid at room temperature,” said Chuan Zhao, researcher at the university and senior author of the team’s report. “They are non-volatile, so this overcomes one of the main problems in making useful miniaturized devices — rapid evaporation of the solvents on the chip.”
The ionic liquids are chemically attached to a gold-coated or glass surface on the new chips, with tiny drops of the liquid arranged into a pattern across the surface. The chemical reactions that occur in these droplets when they come into contact with certain substances are then analyzed. This provides an effective, quick, and potentially mobile way to analyze a wide range of substances.
“We can now carry out many reactions or analytical procedures in ionic liquids at the micro-scale on a chip with enhanced yields and efficiency,” Zhao said. “These microarray chips can be easily produced in high numbers and are very stable. They can survive being turned upside down and heated to 50 degrees (Celsius) and some can even survive being immersed in another liquid.”
Among several other possible applications, these new lab-on-a-chip devices could provide a way for doctors to conduct effective diagnostic work in the field.
“The versatility of our chips means they could have a wide range of prospective functions, such as for use in fast and accurate hand-held sensors for environmental monitoring, medical diagnosis, and process control in manufacturing.”
Image credit: University of New South Wales