Bio-inspired novel carbon dots as fluorescence and electrochemical-based sensors and fluorescent ink.

In the current study, we utilize leaves of Aerva lanata as the precursor to produce carbon dots (CDs) adopting a one-step hydrothermal approach without the use of extra chemical reagents or surface modification. They have hydroxyl and carboxyl groups as surface functionalities, were well soluble in water, were biocompatible, and exhibited bright fluorescence. The applications of the prepared CDs in three broad areas were carefully described. As a fluorescence-based sensor, the prepared sensor was able to sense ciprofloxacin. Ciprofloxacin enhanced the fluorescent intensity of CDs, and a linear correlation between the intensity of fluorescence and the concentration of ciprofloxacin in a wide range with an LOD of 0.4 nM was observed. The mechanism behind the fluorescence enhancement seen with the addition of ciprofloxacin was revealed to be charge transfer and hydrogen bonding. As an electrochemical probe, a carbon dot-modified glassy carbon electrode was able to sense copper ions with good selectivity and an LOD of 4 nM. Cu(II) electrochemical sensing was comprehensively examined, with a complete description of the electron transport process. The anticounterfeiting properties of the synthesized CDs were also proven. The successful real sample analysis also paved the way for an environment-friendly sensor for exhibiting its potential for multifaceted applications. This study not only introduced a new carbon dot to improve our understanding of material properties but also delved into all of its possible applications. [ABSTRACT FROM AUTHOR]