A colorimetric sensor based on nanoparticles was developed for the detection of hydrogen peroxide. Nanoparticles were made using small sheets of poly(methyl methacrylate) (PMMA) and silver nitrate. The optical properties of the solution were characterized by spectrophotometer using the localized surface plasmon resonance (LSPR) phenomenon. The shape and size of the nanoparticles were obtained using a transmission electron microscope (TEM). Silver-poly(methyl methacrylate) nanoparticles solution (AgNP-PMMA) proved to be particularly sensitive to hydrogen peroxide compared to other analytes. This sensor provided a quick, practical and easy tool to detect hydrogen peroxide.

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This work describes experimental results concerning the chemical composition of the alloy patina and inlays from the medieval copper alloy door of the cathedral of Troia (southern Italy), dating back to 1127 CE. The analyses were conducted in situ with no sampling or sample preparation required, using a portable energy-dispersive X-ray fluorescence (ED-XRF) instrument. The compositional results show that the two door leaves were made using a binary alloy of copper and lead, while the nails, lion protomes, and handles have a different chemical composition. Moreover, the analyses revealed uniform concentrations of chlorine, probably due to cleaning treatments during the restoration. It is important to emphasise that the obtained results are the only ones related to this valuable masterpiece analysed.

This paper reports the analyses carried out on the medieval copper alloy door (1111–1118 AD) of the mausoleum of Boemondo d’Altavilla in Canosa di Puglia (Southern Italy). The studied door is the smallest medieval bronze door extant in Italy and, unlike the other Byzantine doors, was most probably made in Canosa di Puglia and not in Constantinople. Analyses were performed to assess the chemical composition of the alloy patinas using a portable energy dispersive X-ray fluorescence (ED-XRF) instrument designed at the University of Salento. The experimental results suggested that the two door leaves have the same chemical composition, even if they appear different in both style and size. Furthermore, the alloy used for the door is different from the other previously-analyzed Byzantine bronze doors. The obtained results can be used in the future to compare the chemical composition of other Byzantine doors in order to better understand the manufacture of these precious artifacts.

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