Polymeric Labs on a Chip for Sustainable Development

Sustainable development is a process involving the society, the environment and the economy to meet human needs while preserving the environment. Sustainable development not only addresses the present needs but also the future needs of humanity. Lab on a chip technologies play an important role in this process. This paper reports examples of low-cost polymeric lab-on-a-chip (LOC) devices for sustainable development in food supply, namely the detection of genetically modified organisms (GMOs) and the detection of insecticides in agriculture. As the first example, the paper presents a close-loop ferrofluid-driven LOC for rapid amplification and detection of GMOs. Polymerase chain reaction (PCR) sample was contained in a circular closed microchannel and driven by magnetic force generated by an external magnet through a small oil-based ferrofluid plug. Successful amplification of genetically modified soya and maize were achieved in less than 13 minutes. The LOC provides a cost saving and less time-consuming way to conduct preliminary screening of GMOs. As the second example, the paper reports a LOC for detection of organophosphorus insecticides for occupational hygiene in agriculture. Nerve agent sarin diluted in water was used to test the device concept. The sample was tested for trace levels of regenerated sarin using immobilised cholinesterase on the chip. Activity of immobilised cholinesterase was monitored by enzyme-assisted reaction of a substrate and reaction of the end-product with a chromophore. Resultant changes in chromophore-induced absorbance were recorded on the. Loss of enzyme activity obtained prior and after passage of the treated blood sample, as shown by a decrease in recorded absorbance values, indicates the presence of either free or regenerated nerve agent in the sample.