Portable paper-based sheet for visual detection of ethyl carbamate in Chinese Baijiu based on aptamer recognition and laccase-like activity of cubic Ag2O nanoparticles

Ethyl carbamate (EC) is a small compound produced and stored during fermentation processes from ethanol, urea, citrulline, and carbamoyl phosphate. EC is commonly found in fermented foods and alcoholic beverages. Prolonged exposure to EC can cause nervous system diseases and liver damage in human beings. EC lacks stable physicochemical properties, and the presence of numerous interfering substances in alcoholic beverages poses challenges for its detection. Herein, it is found that EC1-34 aptamer bound to EC can enhance the laccase-like activity of cubic Ag 2 O nanoparticles (NPs). Subsequently, Ag 2 O NPs are wrapped with EC1-34 aptamer to prepare recognition probes, which are immobilized on a carrier membrane. Thus, a portable paper-based sheet for EC detection in Chinese Baijiu is designed. The visual detection limit of the developed paper-based sheet for EC is 10 μg⋅L −1 , and shows an outstanding linear relationship within the range of 10–200 μg⋅L −1 . Moreover, this colorimetric paper-based sheet has a good practicality in various Chinese Baijiu samples. It is believed that such paper-based sheet can facilitate portable inspection for EC in Baijiu, and may also become a beneficial tool for monitoring EC molecules in other fermented foods.