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A reduced polyoxometalate (POM) functionalized with bisphosphonate (BP) ligands possessing antitumoral properties was used to synthesize metallic gold nanostars (AuNSs) with high reproducibility through a silver-assisted seed growth method. Notably, this study is the first to employ a reduced polyoxometalate as a dual-function reducing and capping agent in the synthesis of gold nanostars. The resulting AuNS@POM composites, characterized by a plasmon band located at 744 nm, combine in a single hybrid nanocomposite alendronate ligands, Mo-(VI) ions, and Au0 centers. The colloidal stability of AuNS@POM was demonstrated in a biological culture medium, and cell experiments were performed to study its antitumoral activity on U87 and MCF7 cell lines from glioblastoma and liver cancer, respectively. First, it was established that the antitumoral activity of the BP POM is enhanced due to the Mo-(V) to Mo-(VI) oxidation process that occurs during AuNS formation. Second, it has been shown that in the presence of the composite, cellular metabolic activity decreases drastically under the effect of irradiation at 808 nm, even leading to almost complete cell death. AuNS@POM therefore exhibits strong antitumor chemo–photothermal activity, paving the way for the development of a type of dual therapeutic agent operating under near-infrared irradiation. [ABSTRACT FROM AUTHOR]

The interaction of incident light with noble metal nanoparticles engenders a fascinating phenomenon known as localized surface plasmon resonance (LSPR). This results in the presence of single or multiple intense absorption bands in the visible to near-infrared spectral range whose position is affected by the refractive index of the surrounding medium. In this comprehensive study, we thoroughly investigated the experimental parameters governing the size, aspect ratio, and optical properties of hollow gold nanoshells (hAuNSs) synthesized through the galvanic exchange of cobalt-based nanospheres. Subsequently, we rigorously determined both the empirical and the theoretical refractive index sensitivity (RIS) and figure of merit (FoM) of these engineered nanostructures. Notably, hAuNS with an external diameter of 98 nm and a shell thickness of 13 nm demonstrated a noteworthy RIS of 360 nm/RIU and an FoM of 2.0 in solution. In contrast, solid gold nanospheres (sAuNSs) of a similar diameter exhibited a significantly lower RIS of 136 nm/RIU. Following the transfer of both of these nanostructures onto glass slides for the development of LSPR sensors, it was intriguing to note that the RIS and FoM remained largely unaffected. These findings underscore the potential of these plasmonic nanoparticles as promising candidates for the design of sensitive solid-phase LSPR sensing devices. [ABSTRACT FROM AUTHOR]

Abstract: The sintering behavior and dielectric properties of the 16CaO–9Li2O–12Sm2O3–63TiO2 (abbreviated CLST) ceramics with different amounts of BaCu(B2O5) (abbreviated BCB) addition were investigated in this paper. The sintering temperature of the CLST ceramics was efficiently lowered by 250 ∘C. The CLST ceramics doped by small amounts of BaCu(B2O5) could be well sintered at 1050 ∘C and possesses good dielectric properties. Especially, the 4 wt% BaCu(B2O5)-doped CLST ceramics sintered at 1050 ∘C for 2 h have optimum dielectric properties of Kr=81.4 and . Obviously, BaCu(B2O5) could be used as a suitable sintering aid that could improve densification of the CLST ceramics at very low temperature. [Copyright &y& Elsevier]