Title: Sensitive Detection of Nitrate using a Paper-based Microfluidic Device

Abstract:

In this paper, we report a simple and inexpensive paper-based microfluidic device for detecting nitrate in water. This device incorporates two recent developments in paper-based technology suitable for nitrate detection and has an optimized microfluidic design. The first technical advancement employed is an innovative fibrous composite material made up of cotton fibers and zinc microparticles that can be incorporated in paper-based devices and results in better nitrate reduction. The second is a detection zone with an immobilized reagent that allows the passage of a larger sample volume. Different acids were tested—citric and phosphoric acids gave better results than hydrochloric acid since this acid evaporates completely without leaving any residue behind on paper. Different microfluidic designs that utilize various fluid control technologies were investigated and a design with a folding detection zone was chosen and optimized to improve the uniformity of the signal produced. The optimized design allowed the device to achieve a limit of detection and quantification of 0.53 ppm and 1.18 ppm, respectively, for nitrate in water. This accounted for more than a 40% improvement on what has been previously realized for the detection of nitrate in water using paper-based technology.

Biography:

Amer Charbaji is a research assistant at the Microfluidics Laboratory at the University of Rhode Island where he is currently pursuing his PhD. His research work includes developing paper-based microfluidic devices for nutrient detection in marine environments. He received his Bachelor of Engineering degree from the American University of Beirut and his Master of Science degree from the University of Maryland at College Park, both in mechanical engineering. He also worked in the industry in Nigeria and Dubai before joining the PhD program at URI.