Quantum dots (QDs) are fluorescent semiconductor nanoparticles but behave as an atom because they have electron energy levels that can absorb and emit light at specific wavelengths. The optical properties of QDs can be changed depending upon the size of the nanoparticle due to the fact that energy is correlated to wavelength. Historically, nanocrystal preparation methods have involved chemically inert ligands that are post-synthetically exchanged from the surface of the crystal to a more useful and/or fitting molecule for the given application. The Niezgoda lab strives to utilize novel, purpose-designed ligands in the synthesis of QDs. The surface of these new ligand molecules are manipulated post-synthetically without fully removing the ligand from the surface of the quantum dots. We have come to label this process “on-particle ligand modification” (OPLM), as it eschews the ligand exchange process that is ubiquitous in studies involving alteration of QD surface chemistry. Here, in line with the overarching theme of the Niezgoda lab, we present our preliminary findings on the preparation of CdSe QDs utilizing a native terminal alkyne ligand, 10-undecynoic acid (UDYA), as the lone surface-bound molecule. Further, core/shell architectures of these particles have been prepared with decent quantum yields in the visible spectrum. These UDYA-coated QDs will be utilized in a hydroamination reaction. This is a catalytic process that adds a nitrogen-hydrogen bond from an amine across the alkyne, which in this case is the surface of the ligand on the QDs.

As-synthesized alkyne-coated CdSe quantum dots for site-directed nanoparticle-substrate chemical linkage

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