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.

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 functionalized. 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 multiple myeloma progression.