Ethylenediamine assist preparation of carbon dots with novel biomass for highly sensitive detection of levodopa

Levodopa (L-Dopa), a precursor drug for dopamine has been widely used to treat Parkinson's disease. However, excess accumulation of L-Dopa in the body may cause movement disorders and uncontrollable emotions. Therefore, it is vital to monitor L-Dopa levels in patients. In this study, a carbon dot (CD)-based fluorescence sensing system was developed for sensitive detection of L-Dopa. The CDs were prepared using a novel biomass, Pandanus amaryllifolius Roxb., as a carbon source via a simple hydrothermal method. Interestingly, it was found that ethylenediamine doping in the preparation system increased the quantum yield of CDs, as well as their fluorescence response sensitivity to L-Dopa. After optimizing the preparation and sensing conditions, the detection limit of L-Dopa decreased from 1.54 μM to 0.05 μM. A complete methodological validation was conducted and the probe was successfully applied to the determination of L-Dopa in fetal bovine serum with excellent precision (RSD ≤ 2.99%) and recoveries of 88.50–99.71%. Overall, this work provides an effective strategy for the regulation of properties of CDs derived from biomass and an innovative method for clinical L-Dopa monitoring.