Paper-based lateral flow assays: Prediction of methanol content in alcoholic beverages

This study introduces an innovative Grade 1 paper-based microfluidic device designed for the rapid, sensitive, and cost-effective detection of methanol in alcoholic beverages. The device integrates chemical reagents and sample fluid on a single paper strip, facilitating a straightforward and portable testing mechanism. The detection of methanol is achieved through a colorimetric reaction involving potassium permanganate, sulfuric acid, sodium bisulfite, and chromotropic acid. Upon interaction with methanol, the reagent mixture produces a distinct color change to purple, which can be visually assessed or quantified. The device works well with small sample volumes (usually less than 50 μl), making it ideal for field applications with minimal resources. The experimental validation confirmed that the device can detect methanol concentrations ranging from 5% (v/v) to 30% (v/v). This range of detection encompasses the critical concentrations found in contaminated alcoholic beverages responsible for methanol poisoning. In addition, numerical simulations were conducted at various time intervals for methanol concentrations, leading to the development of a colorimetric index specifically for measuring alcohol concentration ranging from 5% to 30% (v/v). Furthermore, experiments on both branded and locally made alcoholic beverages validated the accuracy of our developed colorimetric index. This paper-based technology provides various benefits compared to conventional methods, such as lower expenses, simplicity of operation, and the possibility of large-scale manufacturing and distribution in areas with limited resources.