Doxorubicin detection in plasma and blood using a luminescence turn-off nanosensor based on alloyed CdZnSeS/ZnS quantum dots.

The feasibility of doxorubicin (Dox) detection in plasma and blood using a luminescence turn-off nanosensor based on alloyed CdZnSeS/ZnS quantum dots (QDs) is demonstrated. The QD luminescence quenching in the presence of Dox was carefully examined. Optimal assay conditions were selected, including plasma dilution and QD concentration. The calculated limit of detection value was 0.02 µg/mL. Time-resolved QD luminescence quenching and absorption measurements allowed us to determine that the quenching process occurs via a combined mechanism. At low Dox concentrations, the dynamic quenching is predominant, while at Dox concentrations above 2.5 μM, the contribution of static quenching increases drastically. Dox detection in whole human blood was performed and compared with other methods for the drug detection in blood. The results of the method are comparable with those of the high-performance liquid chromatography with ultraviolet-visible detection.