Publications by authors named "Alexandre M P Botas"

Two three-dimensional (3-D) polycyanidometallate-based luminescent thermometers with the general formula {LnCo(CN)(4-benpyo)(HO)·7HO} Ln = (Dy(III)(), Eu(III)()), based on the red-emissive diamagnetic linker [Co(CN)] and the bulky pyridine derivative that possesses the N-oxide moiety, 4-benzyloxy-pyridine N-oxide (benpyo), were prepared for the first time. The structure of compound has been determined by single-crystal X-ray crystallography while the purity and structure of have been confirmed by CHN, Fourier transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (PXRD) analysis. Magnetic AC susceptibility measurements at zero field show no single-molecule magnet (SMM) behavior indicating fast relaxation operating in .

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The 1 : 1 : 1 reaction of YbCl·6HO, K[Co(CN)] and bpyO in HO has provided access to a complex with formula [YbCo(CN)(bpyO)(HO)]·4HO (1) in a very good yield while its structure has been determined by single-crystal X-ray crystallography and characterised based on elemental analyses and IR spectra. Magnetic susceptibility studies showed the complex to be a field induced single molecule magnet, as confirmed by μ-SQUID measurements. CASSCF calculations confirm the existence of a = 7/2 ground state, with rather large transverse components, responsible for the fast relaxation characteristic of compound 1 at zero DC field, which is reduced upon application of DC fields.

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Gold nanoparticles (AuNPs) are one of the most studied nanosystems with great potential for biomedical applications, including cancer therapy. Although some gold-based systems have been described, the use of green and faster methods that allow the control of their properties is of prime importance. Thus, the present study reports a one-minute microwave-assisted synthesis of fucoidan-coated AuNPs with controllable size and high antitumoral activity.

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Transparent upconverting hybrid nanocomposites are exciting materials for advanced applications such as 3D displays, nanosensors, solar energy converters, and fluorescence biomarkers. This work presents a simple strategy to disperse upconverting β-NaYF:Yb/Er or Tm nanoparticles into low cost, widely used and easy-to-process polydimethylsiloxane (PDMS)-based organic-inorganic hybrids. The upconverting hybrids were shaped as monoliths, films or powders displaying in the whole volume Tm or Er emissions (in the violet/blue and green/red spectral regions, respectively).

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In this communication, we report the post-synthetic functionalization of K+/Ni2+/[Cr(CN)6]3- Prussian blue analogue (PBA) nanoparticles by the 2-aminoanthracene luminophore to yield a bifunctional magneto-luminescent nanosystem. The photoluminescence properties of the fluorophore are found modified by the confinement effect upon adsorption, while the magnetic behavior of PBA is preserved.

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The investigation of nanoparticles and their interaction with bio-macromolecules have become an important issue; the widely discussed protein corona around nanoparticles and their biological fate in general have drawn particular attention. Here, we focus on nanoclay dispersions and the use of solvatochromic fluorescent dyes (Dansyl and Coumarin 153) for monitoring the interaction with two model proteins, bovine serum albumin and β-lactoglobulin. On one hand, these dyes are poorly emissive in water, but experience a boost in their fluorescence when adsorbed into the hydrophobic domains of proteins.

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The light emission properties of silicon crystalline nanoparticles (SiNPs) have been investigated using steady-state and time-resolved photoluminescence measurements carried out at 12 K and at room temperature. To enable a comparative study of the role of surface terminal groups on the optical properties, we investigated SiNPs-H ensembles with the same mean NP diameter but differing on the surface termination, namely organic-functionalized with 1-dodecene (SiNPs-C12) and H-terminated (SiNPs-H). We show that although the spectral dependence of the light emission is rather unaffected by surface termination, characterized by a single broad band peaking at ∼1.

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