Carbon dot-based molecularly imprinted polymer fluorescent sensor for the detection of propranolol in plasma

Propranolol, a medication used to treat cardiovascular diseases, can be harmful when overdosed and hazardous to ecosystems if released into the environment. Here, a new molecularly imprinted fluorescent sensor was developed from carbon dots through a sol-gel method. Carbon dots served as both the fluorescent signal and the carrier, with propranolol as the template molecule and 3-aminopropyltriethoxysilane as the functional monomer to be grafted on carbon dots' surface. A novel detection method was established for the efficient, rapid, and cost-effective detection of propranolol in human plasma through quantitative analysis by using a fluorescence spectrophotometer and an ultraviolet spectrophotometer. Under the optimal conditions, the detection range of 0.5-4 mg L-1, the detection limit of 0.092 mg L-1, the imprinting factor of 2.42, and the detection response time of 2 min were achieved. The prepared carbon dot-based molecularly imprinted fluorescent sensor was proved to have a wide accurate linear range, low detection limit, and very short response time, and can detect lower analyte concentrations with higher detection accuracy.

A Novel Voltametric Measurements of Beta Blocker Drug Propranolol on Glassy Carbon Electrode Modified with Carbon Black Nanoparticles

A new voltametric method for highly sensitive propranolol (PROP) determination was developed. A glassy carbon electrode modified with a hybrid material made of carbon black (CB) and Nafion was used as the working electrode. The preconcentration potential and time were optimized (550 mV and 15 s), as well as the supporting electrolyte (0.1 mol L⁻¹ H₂SO₄). For 15 s preconcentration time, linearity was achieved in the range 0.5–3.5 μmol L⁻¹ and for 120 s in 0.02–0.14 μmol L⁻¹. Based on the conducted calibration (120 s preconcentration time) limit of detection (LOD) was calculated and was equal to 7 nmol L⁻¹. To verify the usefulness of the developed method, propranolol determination was carried out in real samples (tablets and freeze-dried urine). Recoveries were calculated and were in the range 92–102%, suggesting that the method might be considered as accurate. The repeatability of the signal expressed as relative standard deviation (RSD) was equal to 1.5% (n = 9, PROP concentration 2.5 µmol L⁻¹). The obtained results proved that the developed method for propranolol determination might be successfully applied in routine laboratory practice.