Histamine-responsive dye-incorporated carbon dots for visual monitoring of food spoilage

With food safety problems abounding, it is essential to explore some efficient and effective methods for monitoring food quality. To this end, we have developed a histamine-responsive carbon dots (CDs)-based sensing system for visual monitoring of food spoilage. In this system, the aldehyde group on the surface of CDs serves as the recognition sites to combine with the amino group on histamine to form a Schiff base that effectively enhances the fluorescence. On the other hand, 1-aminoanthraquinone (ANQ) was introduced as a reference signal to endow the fluorescent probe with self-calibrating capacity. As the histamine concentration increases, linear ratiometric response was obtained accompanied with a distinguishable fluorescence color change from red to blue. Besides, test strips-based smartphone visual assays were successfully used to evaluate and monitor the histamine levels in fish samples. Our proposed sensing strategy has been demonstrated to be efficient and robust along with great potential for real-time visual monitoring of food spoilage.