NFC-enabled Sensing Platform for the Onsite Determination of Asparagine in Food

Cooking foods rich in free asparagine (an amino acid that plays an important role in the synthesis of proteins), such as potatoes and flour-based products, can lead to the formation of acrylamide, a potent neurotoxin and potential carcinogen. Food manufacturers must quantify the levels of free asparagine before processing to minimize the formation of acrylamide, but conventional detection methods are often slow and expensive. We report a point-of-need measurement technology consisting of a chemically-functionalized paper-based electrical gas sensor and Near Field Communication (NFC)-enabled digital sensor interface (an integrated circuit) for rapid, cost-effective detection of free asparagine. Acid-functionalized paper-based electrical gas sensors selectively responds to ammonia gas, which is released during the enzymatic degradation of free asparagine. Through the use of the NFC-enabled digital sensor interface, a smartphone can wirelessly power and operate the paper-based gas sensor, enabling real-time quantification of free asparagine with a dedicated mobile application. We demonstrate a proof-of-concept sensor with a limit of detection of 3.19 µg/mL, capable of detecting low levels of free asparagine in food products. This practical tool can facilitate better control over the levels of acrylamide in food and improve food safety.