Highly Sensitive and Selective Detection of Amoxicillin Using Carbon Quantum Dots Derived from Beet

In the present work, we synthesized the carbon quantum dots (CQDs) by one step hydrothermal method using the dried beet powder as the carbon source without additional chemical reagents and functionalization. The as-prepared CQDs are quasi-spherical carbon nanoparticles with diameters of 4–8 nm as well as surface functional groups such as carboxyl and hydroxyl groups, and exhibit good water-solubility, biocompatibility, and strong fluorescence. It is confirmed that amoxicillin (AMO) could enhance the fluorescent intensity of CQDs, the I/I₀ showed a linear correlation between the intensity of fluorescence and the concentration of AMO in a broad range. These superior properties render a potential application of the CQDs in biomedical.