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The biogenic synthesis of nanomaterials, i.e., synthesis carried out by means of living organisms, is an emerging technique in nanotechnology since it represents a greener and more eco-friendly method for the production of nanomaterials. In this line, in order to find new biological entities capable of biogenic synthesis, we tested the ability of some extremophilic microorganisms to carry out the biogenic production of AgNPs and SeNPs. Silver NPs were produced extracellularly by means of the thermophilic Thermus thermophilus strain SAMU; the haloalkaliphilic Halomonas campaniensis strain 5AG was instead found to be useful for the synthesis of SeNPs. The structural characterization of the biogenic nanoparticles showed that both the Ag and Se NPs possessed a protein coating on their surface and that they were organized in aggregates. Moreover, both types of NPs were found be able to exert an interesting antibacterial effect against either Gram-positive or Gram-negative species. This study confirmed that extremophilic microorganisms can be considered valuable producers of biologically active nanoparticles; nevertheless, further experiments must be performed to improve the synthesis protocols in addition to the downstream processes. [ABSTRACT FROM AUTHOR]

Ibuprofen is one the most used non-steroidal anti-inflammatory drug, which is considered an emerging pollutant that may contaminate surface and underground water. Photodegradation using nanomaterials is one of the most sustainable and cheap technologies that can be used in water purification. In this study, the photodegradation efficiency of in-house prepared ceria (CeO 2) nanostructured materials towards ibuprofen was assessed under UV irradiation. CeO 2 nanoparticles (NPs) were prepared through wet-chemical synthesis and characterized by several techniques. The photodegradation activity of the synthesized CeO 2 -NPs was compared to the commercial Aeroxide TiO 2 -P25. Small crystalline CeO 2 -NPs were obtained with about 15 nm particle size, band-gap of 3.1 eV with irregular morphology. The surface area of CeO 2 -NPs was estimated to be 76 ± 5 m2/g. Dynamic light scattering analysis revealed that these nanoparticles have a strong tendency to self-aggregate and to form clusters in aqueous suspension. The results showed a slightly better performance of Aeroxide TiO 2 -P25 compared to CeO 2 -NPs. On the other hand, five reusability tests confirmed the stability of CeO 2 -NPs in the reaction conditions, without any significant effect on their photodegradation activity. The goodness of the kinetic modeling of the experimental data was proven through the estimated kinetic parameters, together with the statistical information. The temperature effect confirmed that the higher the temperature, the greater the dissociation rate. Thus, there is a direct relationship between temperature, reaction rate, and the activation energy for each reaction. Furthermore, the thermodynamic parameters, namely: changes in Gibbs free energy (∆ G °) , enthalpy (∆ H °) , and entropy (∆ S °) have been reported revealing the efficient photodegradation performance of CeO 2 -NPs. [Display omitted] • Ibuprofen is considered an emerging water pollutant. • CeO 2 nanoparticles (NPs) were prepared through wet-chemical synthesis. • CeO 2 -NPs were characterized by XRD, XPS, TEM, DLS, and UV-Vis DRS techniques. • The photodegradation activity of CeO 2 -NPs was compared to Aeroxide TiO 2 -P25. • Reusability tests confirmed the stability and the sustainability of CeO 2 -NPs. [ABSTRACT FROM AUTHOR]

[Display omitted] Halloysite nanotubes (HNTs) represent a versatile core structure for the design of functional nanosystems of biomedical interest. However, the development of selective methodologies for the site-controlled functionalization of the nanotubes at specific sites is not an easy task. This study aims to accomplish a procedure for the site-selective/specific, "pin-point", functionalization of HNTs with polydopamine (HNTs@PDA). This goal was achieved, at pH 6.5, by exploiting the basicity of ZnO nanoparticles anchored on the HNTs external surface (HNTs@ZnO) to induce a punctual polydopamine polymerization and coating. The morphology and the chemical composition of the nanomaterial was demonstrated by several techniques. Turbidimetric analysis showed that PDA coating affected the aqueous stability of HNTs@PDA compared to both HNTs@ZnO and HNTs. Notably, hyperthermia studies revealed that the nanomaterial induced a local thermic rise, up to 50 °C, under near-infrared (NIR) irradiation. Furthermore, secondary functionalization of HNTs@PDA by selective grafting of biotin onto the PDA coating followed by avidin binding was also accomplished. [ABSTRACT FROM AUTHOR]