Green synthesized carbon dots as antibiotics sensor and fluorescent ink

Nearly all antibiotics cause significant health issues and environmental risks due to their unrestricted intake and delayed consumption. So, their detection and removal are of great concern. In this work, a novel Coleus zeylanicus leaves-derived nitrogen doped carbon dot (NCDs) based sensor was developed for the detection of antibiotics. The NCDs were synthesized via cost effective hydrothermal method. The NCDs with amorphous nature have an average size of 2.59 nm and a surface charge of -30.89 mV and exhibited excellent stability towards various experimental conditions. The NCDs worked as a fluorescent probe for levofloxacin (LEV) detection and an electrochemical sensing probe for the detection of amoxicillin (AMX). The fluorescence of NCDs was enhanced by LEV, and the limit of detection is obtained as 0.06 µM. The NCDs detected AMX with a LOD of 0.03 nM. Additionally, the effectiveness of NCDs in sensing levofloxacin and amoxicillin was confirmed in spiked water samples. Also, the role of NCDs as fluorescent ink was explored. In light of the findings of this study, it could be possible to find new ways to address environmental issues using carbon dots from sustainable sources.