Size-dependent emission kinetics and sensing capabilities of CdSe quantum dots functionalized with penicillamine ligands

- Hydrophobic CdSe QDs were functionalized with l- and d-penicillamine molecules and transferred to nontoxic water environment.
- The influence of ligand exchange procedure on the optical and electronic properties of CdSe QDs have been investigated.
- The changes in nanosecond and picosecond time scale kinetics upon CdSe QDs surface functionalization were investigated.
- The studied system allowed for selective interaction with chiral drug showing the possible applications in chirality dependent sensing.

The ligand induced chirality in semiconducting nanoparticles has recently gained special attention, due to possible application of chiral nanoparticles as optically active probes in enantioselective bio-sensing. However, the exact mechanisms of chiral organic ligands interaction with quantum dots surfaces are still not fully described. We have performed ligand exchange procedure in order to obtain water soluble CdSe QDs functionalized with left- and right-handed enantiomers of penicillamine molecules and the influence of such post-synthetic surface treatment on the optical properties of CdSe QDs with respect to their size has been investigated. In particular, picosecond and nanosecond time scale kinetics revealed strong hole trapping at the thiol molecules near to the quantum dots surfaces. Additionally, possible applications of chiral drug discrimination are shown for L- and D-penicillamine functionalized CdSe quantum dots.

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