Atomic Absorption Spectrometry as an Alternative to Determine the Presence of Gold Nanoparticles on or in Silica Matrix

Two different gold-silica-based nanomaterials were prepared: (i) silica-supported gold nanoparticles (AuNP/SiO2); and (ii) gold-silica core-shell (AuNP@SiO2). Three strategies for sample treatment (S), consisting in acid treatments, employed: (S1) HNO3; (S2) HNO3 + HCl; (S3) HF HCl, applying microwave oven digestion S2 S3. From three calibration curves, slope, intercept, linear correlation coefficient obtained. The accuracy of the methods was evaluated by comparing contents a determined flame atomic absorption spectrometry (FAAS) inductively coupled plasma emission (ICP-OES). Finally, amount all samples FAAS. UV-Vis spectroscopy transmission electron microscopy (TEM) used to compare material before after treatment. By comparison, application S3 allowed presence on or silica matrix be quantified.