Sahar Khaksar Haghani, Ali A. Ensafi , Nafiseh Kazemifard, and Behzad Rezaei,

Abstract—In this study, an optical sensor has been suggested to measure a trace amount of metronidazole (MTZ). In the first step, an eco-friendly method was used to synthesize carbon dots (CDs) using Eucalyptus leaves for the first time. The obtained CDs showed high solubility in water and high fluorescence intensity. In the next step, the CDs was used as a fluorescence probe for the determination of MTZ. This probe was modified with a sensitive MTZ silica, which was sensitized using imprinting technology. The sensitive composite called CDs@MIPs demonstrated a linear range from 0.4 to 10.0 µg L−1 with a detection limit to 0.2 µg L−1. High sensitivity, excellent selectivity, ease of fabrication, cheapness, and use of an environment-friendly method to synthesize the fluorescence probe are the advantages of this method. The suggested optical sensor with these desirable features is an attractive method to fast determine of MTZ. Index Terms—Metronidazole, carbon dots, eucalyptus, optical sensor, molecularly imprinted polymer.