Determination of amines based on their interaction with QDs: Effect of the formation QD-assemblies

Assemblies of closed nanoparticles have focused interest because they exhibit new optical and chemical properties. The use of a 1D covalent strategy for quantum dots-assemblies has been proposed in this work as novelty. It was studied the effect of use different dithiols, including aromatic and aliphatic dithiol compounds, on the formation of QDs-assemblies in order to establish the influence of the linker's structure on the geometry of the assemblies, and hence on their properties. As a second part of the work, the changes on analytical response to analytes thanks to the formation of QDs-assemblies when dithiols are added were studied for firs time. For this study, some biogenic amines were selected as target analytes. We observed an improvement of 2.7–4 times in the sensitivity, expressed as slope of the calibration graph, when the dithiols were added to the system obtaining QDs-assemblies.

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► Formation of quantum dots-nanochains assisted by the covalent linking through bifunctional dithiol molecules.
► With time, the extent of chain assembly and network formation became enhanced and interconnectivity between chains was observed.
► The optical properties changed as a function of the total length of the structure.
► Fluorescence response of QDs towards amines was enhanced after the formation of QD-assemblies induced by the presence of dithiol molecules.