Green preparation of carbon dots from Momordica charantia L. for rapid and effective sensing of p-aminoazobenzene in environmental samples

p -Aminoazobenzene ( p AAB) is a hazardous azo dye that causes considerable harm to human health and the environment. The development of novel and sensitive sensors for the rapid detection of p AAB is in high demand. In this study, a simple fluorescent sensor for p AAB detection is designed based on carbon dots (CDs) which are prepared using green carbon source of Momordica charantia L. via a facile hydrothermal approach. The fluorescence spectra of CDs exhibit considerable overlap with the absorption band of p AAB, and the fluorescence is specifically suppressed in the presence of p AAB ascribed to the inner filter effect. Good and wide linearity is observed in the p AAB concentration range of 0.01–12.5 μg mL −1 with a lower detection limit of 3.9 ng mL −1 . The established method achieves good results with a rapid analysis of p AAB in different practical water and soil samples. The as-constructed fluorescent sensor provides a simple, rapid, economical and eco-friendly platform and possesses prospective applications for the effective, selective and sensitive detection of p AAB in the environmental field.