Fluorescent carbon dots were prepared via a simple and straightforward one-step pyrolytic process using N-hydroxysuccinimide. The prepared C-dots present remarkable photoluminescence with blue to green shifting emission and absolute quantum yields varying from 14 to 31% as a function of the excitation wavelength and selected dispersion media. Interestingly, up-conversion from NIR to the visible range was not only instrumentally recorded but even visually observable. Further, the composition and morphology of the prepared C-dots were studied using XPS, FT-IR, Raman, P-XRD, DLS and AFM as investigation methods. Since the majority of C-dot studies are biased towards fluorescent labeling in cellular imaging, their photoluminescence properties, physicochemical stability and ease of fabrication are expected to play a key role in applications ranging from sensors to efficient solar energy conversion or high performance optoelectronic devices.
The synthesis of the β-cyclodextrin/propiconazole nitrate inclusion complex and the advantages of the encapsulation of this drug were recently reported, but the experimental data only partially revealed the structure of the supramolecular complex due to the limitations in understanding the intermolecular association mechanism. The present work describes the equilibrium molecular geometries of β-cyclodextrin/propiconazole and β-cyclodextrin/protonated propiconazole, established by the AM1 and PM3 semi-empirical methods. The affinity between different parts of the guest molecule and the cyclodextrin cavity was studied considering that propiconazole possesses three residues able to be included into the host cavity through primary or secondary hydroxyl rims. The results have revealed that the most stable complex is formed when the azole residue of the propiconazole enters the cavity of the cyclodextrin through the narrow hydroxyl’s rim.