A cellulosic paper-based sensor for detection of starch contamination in milk

Chemical and biomolecular analysis form an integral part of food contamination testing and healthcare diagnostics. The majority of the currently established detection methods are expensive, sophisticated and time consuming. Microfluidic-based lab-on-a-chip systems offer a promising alternative in this regard by enabling the development of simpler and relatively cost-effective platforms for analytical applications. In this work, we report the fabrication of a portable sensor platform using selective wax impregnation of cellulosic paper. The application of the fabricated paper-based lab-on-a-chip device is demonstrated for the qualitative and quantitative detection of starch contamination in milk using colorimetry. Integration of a detection procedure with smartphone imaging allows for on-the-spot data collection, thus overcoming the challenges of sample storage, handling and transportation to lab facilities. This approach offers a versatile method for diagnostic and sensing applications in resource-limited areas, especially in developing and underdeveloped countries.