Rapid detection of olive oil blends using a paper-based portable microfluidic platform

Abstract

This paper presents an application of a portable microfluidic platform based on a filter paper on which multi-walled carbon nanotubes were deposited to quickly determine the quality of olive oil by measuring electrical resistance. Three different types of filter paper with different pore sizes and different filtration rates were used in the middle of the microfluidic platform, as a material for soaking a blend of olive and high-oleic sunflower oil. The rapid prototyping xurographic technique was used to fabricate the complete microfluidic platform. For testing purposes, oil blends in various proportions were deposited through the inlet on the top of the platform. The variation in electrical resistance at room temperature was measured, using the Chemical Impedance Analyzer, successfully indicating oil proportions in measured blends. We obtained the change of resistance in the range from 0.26 MΩ to 2.79 MΩ per percentage of olive oil content, for corresponding linearity index from 0.71 to 0.99, for papers labelled with 44–45, respectively. Additionally, a prototype of electronic device was developed for acquisition and displaying measured data, based on the created microfluidic platform.