Abstract

Biogenic amines (BAs) represent a toxicological risk in many food products. Putrescine is the most common BAs found in food and is frequently used as a marker for food quality. Today there is a lack of regulation concerning safe putrescine limits in food as well as outdated food handling practices leading to unnecessary putrescine intake. Conventional methods used to evaluate BAs in food are generally time and resource heavy, limiting the options for on-site analysis. In this work, we developed a transcription-factor based biosensor for quantification of putrescine, one of the BAs in meat products, using a naturally occurring putrescine responsive repressor-operator pair (PuuR-puuO) from Escherichia coli. Moreover, we demonstrate the use of the putrescine biosensor with a paper-based cell-free device that enables low-cost and rapid putrescine detection. The system was validated using a variety of consumer meat samples with comparable performance to standard well-plate analysis methods. We propose that our system is ready for use to assess the safety of meat products will contribute to a new phase of low-cost biosensors designed for food safety.