Highly accessible aqueous synthesis of well-dispersed dendrimer type platinum nanoparticles and their catalytic applications

The application of novel methodologies to the synthesis of nanomaterials is still a challenge in many different technological and scientific fields.New efficient and reproducible synthetic methodologies,that produce fewer residues and reduce the cost of raw materials must be developed.In the present work,we have explored the attractive possibility to apply the cheap iron (Ⅱ) sulphate salt in the reduction process of the K2PtCl4 to produce colloids suspensions.The synthesis took places in water and was assisted by sodium citrate (SC) using polyvinylpyrrolidone (PVP) as a surfactant.The adjustment of this novelty process allows obtaining well-dispersed and sub-20 nm dendrimer-type platinum nanoparticles (Pt D-NPs).The nano-dendrimers produced have been characterized using dynamic light scattering (DLS),transmission electron microscopy (TEM),high-resolution TEM (HR-TEM),XRD spectroscopy,inductive couple plasma (ICP) analysis,Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-vis) spectroscopy.Interesting conformational results derived from the size and shape will be discussed.Catalytic application of the Pt D-NPs has been explored in the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) in aqueous media at room temperature obtained TOF value of 253 min^-1.Finally,our Pt D-NPs were tested as artificial metalloenzyme showing catechol oxidase activity for oxidation of L-DOPA.

Novel nanocomposites based on a strawberry-like gold-coated magnetite （Fe@Au） for protein separation in multiple myeloma serum samples

A new process to produce magnetite partially coated with strawberry-like gold nanoparticles in aqueous media is reported. The fast response to magnetic fields and optical properties of gold nanoparticle-based colloidal systems are the two main advantages of this new Fe@Au nanomaterial. These advantages allow for the use of this new colloidal nanomaterial for various purposes in proteomics and biomedicine, as proteins can bind to the surface, and the surface can also be funcfionalized. As proof-of-concept, the new Fe@Au nanoparticles have been assessed in biomarker discovery as a tool for pre-concentration and separation of proteins from complex proteomes. To this end, sera from healthy people were compared with sera from patients diagnosed with multiple myeloma. The application of this new Fe@Au nanomaterial combined with mass spectrometry has allowed for the identification of 53 proteins, and it has also shown that the heat shock protein HSP75 and the plasma protease C1 inhibitor are potential biomarkers for diagnostics and control of multilvle mveloma vro^ression.

The versatility of Fe(Ⅱ) in the synthesis of uniform citrate-stabilized plasmonic nanoparticles with tunable size at room temperature

A highly versatile seed-mediated approach for the synthesis of citrate-stabilized gold,silver and palladium nanoparticles(NPs)with size control is reported.The use of iron(Ⅱ)as a reducing agent enables the fabrication of monodisperse NPs in a wide range of sizes(from 15 nm to at least 120 nm(90 nm for Pd))at room temperature.The citrate as capping ligand on the NPs surface facilitates its further surface modification with proteins and thiolated molecules.

Water-soluble hollow nanocrystals from self-assembly of AIEEactive Pt(II)metallomesogens

Luminescent hollow micro-and nanocrystals have been successfully obtained taking advantage of the self-assembly behavior and the aggregation-induced emission enhancement properties of several bispyrazolate Pt(II)metallomesogens decorated with four terminal alkyl chains.Oil-in-water droplets have been used to confine the Pt(II)compounds and drive them to be self-assembled via intermolecular Pt…Pt interactions into spherical aggregates of about 200 or 50 nm.Evaporation of the oil phase generates highly-stable aqueous dispersions of nanocrystals that emit a bright orange light as a result of the existence of^(3)MMLCT excited states.Different methods and conditions have been tested for studying the effect of several parameters such as the temperature and the stirring speed in the final particle size and in the polydispersity index.Moreover,the micro-and nanocrystals are able to entrap hydrophobic drugs between the alkyl chains of the compounds,forming stable dispersions of drug-loaded capsules in water.The droplet method is applied in the area of metallomesogens for the first time to synthesize self-assembled Pt(II)nanocapsules,which opens a new field of study that could allow the use of these liquid crystal materials in biomedical applications.