Luminescence behavior of colloid quantum dots in the presence anthracycline antibiotic mitoxantrone: Surface interaction and luminescence quenching, size and composition dependence, potential for clinical study.

The luminescence of colloidal quantum dots (QDs) is often affected by the passivating layer, the stabilizing ligand, and the interactions in solution. The anthracycline antibiotic mitoxantrone (MTX) effectively quenches QDs luminescence while attaching to their surface in the aqua colloid. Careful selection of the architecture of QDs with significant luminescence quenching in the presence of MTX will make future for developing a simple and fast luminescence turn-off method to determine the concentration of MTX. To find the most sensitive QDs architecture to the presence of MTX, two types of nanoparticles were examined as detector systems: (i) a series of size-selected fractions of non-cadmium AgInS/ZnS QDs and (ii) alloyed CdZnSeS and CdZnSeS/ZnS QDs. All tested QDs in aqueous colloids were coated with thioglycolic acid as a surface stabilizing ligand. An examination of luminescence intensity and lifetime decreasing in the presence of MTX allowed us to evaluate the effect of the structure and composition of QDs on the efficiency of luminescence quenching by MTX. A detailed study demonstrates a predominantly static quenching mechanism, via the formation of complexes with high binding constants (∼106-107 M−1). The wide variability in the composition and size of QDs made it possible to achieve a low MTX detection limits (3 and 5 nM for the third fraction of AgInS/ZnS and CdZnSeS/ZnS QDs, respectively). Thus, the use of luminescent QDs as a direct detection system is promising for monitoring MTX concentrations [Display omitted] [ABSTRACT FROM AUTHOR]