Effect of synthesis variables on the characteristics of magnesium hydroxide nanoparticles and evaluation of the fluorescence of functionalised Mg(OH)2 nanoparticles

Deanne J Calderón, I DeAlba-Montero, Facundo Ruiz and Félix Echeverría

Abstract

Nanoparticles (NPs) of magnesium hydroxide appear to be an exceptional nanomaterial due to its biocompatibility and low toxicity. However, the mechanism by which the NPs act in the organism has been very difficult to study. In order to contribute to that challenge, in this work magnesium hydroxide was functionalised with organic fluorophores allowing the material to be traced during an in-vivo experiment. Magnesium hydroxide NPs were obtained by the co-precipitation method and analysed by TEM (Transmission electron microscopy), XRD (x-ray diffraction), Raman spectroscopy (RS) and FTIR (Fourier transform infrared spectroscopy). The effects of reaction time, agitation and stoichiometric ratios of the reagents (MgCl₂:NaOH) on the NPs characteristics were studied. Mg(OH)₂ NPs with average sizes below 65 ± 26 nm were obtained with hexagonal, circular or irregular platelet-shape. NPs with an average size of 41 ± 12 nm were functionalised with curcumin and rhodamine using (3-aminopropyl)-triethoxysilane (APTES) as a coupling agent. It was observed the positive effect of the addition of APTES keeping the Mg(OH)₂ NPs dispersed. Moreover, it was found that incorporating APTES as a binding agent with curcumin quenched the fluorescence of curcumin on nanoparticles.