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Density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations were performed to represent carbon dots surfaces. The addition of different oxygen functional groups to the aromatic carbon core structure and the stability in the interaction with silver nanoparticles was also investigated. Adsorption energies were evaluated in order to compare the competition for adsorption sites on silver surface with D-glucose and D-gluconate ion molecules. The -COOH and -COO groups and the interaction of the latter with silver were proposed to explain some features of the UV-visible absorption spectra, which could also contribute to an explanation for the charge observed on carbon dot surfaces.

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Argentina is a beekeeping country and one of the drawbacks is the exposure of the hives to pollutants. Therefore, the aim of this Thesis is the development of an electroanalytical methods to evaluate the hygienic-sanitary quality of bee products of Buenos Aires province. The following works were performed: ➢ A "lab-made" solid bismuth electrode was designed for cadmium determination in corbicular pollen and raw propolis samples. For this proposed, Square Wave Anodic Stripping Voltammetry was used as electroanalytical technique. ➢ An "in-situ" antimony film electrode was developed for tetracyclines residues determination in honey samples, using Square Wave Cathodic Stripping Voltammetry. ➢ The use of an electrochemically activated glassy carbon electrode and Square Wave Adsorptive Stripping Voltammetry was implemented for the amitraz determination from its final metabolite, 2,4 dimethylaniline, in honey samples. The proposed methods are simple, fast, low cost and may be a good alternative for the determination of these analytes in bee products. Furthermore, the results obtained were satisfactorily validated using recovery study. Certifico que fueron incluidos los cambios y correcciones sugeridas por los jurados

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