Quenching photoluminescence of Carbon Quantum Dots for detecting and tracking the release of Minocycline

  • 10 Jul 2021
  • Published Resarch - Pharmacy


Michel Rahal, Yomen Atassi, Ibrahim Alghoraibi

Published in

Journal of Photochemistry and Photobiology A: Chemistry, Volume 412, Article 113257, March 2021.


This work reports the preparation of Carbon Quantum Dots via one-step microwave-assisted synthesis, to be employed for the determination of Minocycline antibiotic. Linear relationship was observed between photoluminescence quenching of CQDs and Minocycline concentration between 0.28–30.39 μM. UV–vis and PL Spectroscopy revealed that PL decrease arise from Inner Filter Effect. Selectivity studies were conducted to evaluate interference of various compounds on MC detection. In addition, Minocycline was loaded on Chitosan-grafted-oligomeric Lactic Acid microspheres, to be used as a drug carrier of Minocycline. Thereafter, CQDs were used to determine loading capacity, encapsulation efficiency, and cumulative drug release of Minocycline-loaded microspheres. Optimum samples showed loading capacity between 14.1–26.344 %, and encapsulation efficiency between 34.48–64.37%. CHS-g-OLA2 sample showed diminished burst release, and 50 % cumulative drug release during 4 days. Mathematical modelling showed that CHS-g-OLA2 sample follows Higuchi kinetic model, which describes the release of drug from swellable matrix by diffusion.

Keywords: Carbon Quantum - Dots Minocycline - IFE - Drug release.

Link to Abstract