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

Abstract

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.