A facile fluorescent sensor based on nitrogen-doped carbon dots derived from Listeria monocytogenes for highly selective and visual detection of iodide and pH

Sensitive and visual analysis of iodide (I(−)) and pH is significant in environmental and food applications. Herein, we present a facile fluorescent sensor for highly selective and visual detection of I(−) and pH based on nitrogen-doped carbon dots derived from Listeria monocytogenes (NCDs-LM). The NCDs-LM-based fluorescent sensor showed a good linear relationship to I(−) concentrations, and the detection limit was calculated as 20 nmol L(−1). The developed sensor was successfully applied to the detection of I(−) in drinking water and milk samples. Meanwhile, the as-synthesized NCDs-LM sensor can be used to detect pH, achieving a wide linear pH range. Furthermore, fluorescent test papers based on NCDs-LM were designed for semi-quantitative detection of I(−) and pH via the naked-eye colorimetric assay. The present work indicates that the NCDs-LM-based fluorescent sensor has high potential for use in environmental monitoring and food analysis.