The report introduces hybrid polyelectrolyte-stabilized colloids combining blue and green-emitting building blocks, which are citrate carbon dots (CDs) and [TbL]⁺ chelate complexes with 1,3-diketonate derivatives of calix[4]arene. The joint incorporation of green and blue-emitting blocks into the polysodium polystyrenesulfonate (PSS) aggregates is carried out through the solvent-exchange synthetic technique. The coordinative binding between Tb³⁺ centers and CD surface groups in initial DMF solutions both facilitates joint incorporation of [TbL]⁺ complexes and the CDs into the PSS-based nanobeads and affects fluorescence properties of [TbL]⁺ complexes and CDs, as well as their ability for temperature sensing. The variation of the synthetic conditions is represented herein as a tool for tuning the fluorescent response of the blue and green-emitting blocks upon heating and cooling. The revealed regularities enable developing either dual-band luminescent colloids for monitoring temperature changes within 25–50 °C through double color emission or transforming the colloids into ratiometric temperature sensors via simple concentration variation of [TbL]⁺ and CDs in the initial DMF solution. Novel hybrid carbon dots-terbium chelate PSS-based nanoplatform opens an avenue for a new generation of sensitive and customizable single excited dual-band nanothermometers.

In this study, Nickel oxide-based catalysts (Ni_xO_x) were synthesized and used for the in-situ upgrading process of heavy crude oil (viscosity 2157 mPa·s, and API gravity of 14.1° at 25 °C) in aquathermolysis conditions for viscosity reduction and heavy oil recovery. All characterizations of the obtained nanoparticles catalysts (Ni_xO_x) were performed through Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), X-Ray and Diffraction (XRD), and ASAP 2400 analyzer from Micromeritics (USA), methods. Experiments of catalytic and non-catalytic upgrading processes were carried out in a discontinuous reactor at a temperature of 300 °C and 72 bars for 24 h and 2% of catalyst ratio to the total weight of heavy crude oil. XRD analysis revealed that the use of nanoparticles of NiO significantly participated in the upgrading processes (by desulfurization) where different activated form catalysts were observed, such as α-NiS, β-NiS, Ni₃S₄, Ni₉S₈, and NiO. The results of viscosity analysis, elemental analysis, and ¹³C NMR analysis revealed that the viscosity of heavy crude oil decreased from 2157 to 800 mPa·s, heteroatoms removal from heavy oil ranged from S—4.28% to 3.32% and N—0.40% to 0.37%, and total content of fractions (ΣC₈–C₂₅) increased from 59.56% to a maximum of 72.21%, with catalyst-3 thank to isomerization of normal and cyclo-alkanes and dealkylation of lateral chains of aromatics structures, respectively. Moreover, the obtained nanoparticles showed good selectivity, promoting in-situ hydrogenation-dehydrogenation reactions, and hydrogen redistribution over carbons (H/C) is improved, ranging from 1.48 to a maximum of 1.77 in sample catalyst-3. On the other hand, the use of nanoparticle catalysts have also impacted the hydrogen production, where the H₂/CO provided from the water gas shift reaction has increased. Nickel oxide catalysts have the potential for in-situ hydrothermal upgrading of heavy crude oil because of their great potential to catalyze the aquathermolysis reactions in the presence of steam.

The present work demonstrates the optimization of the ligand structure in the series of bis(phosphine oxide) and β-ketophosphine oxide representatives for efficient coordination of Tb³⁺ and Eu³⁺ ions with the formation of the complexes exhibiting high Tb³⁺- and Eu³⁺-centered luminescence. The analysis of the stoichiometry and structure of the lanthanide complexes obtained using the XRD method reveals the great impact of the bridging group nature between two phosphine oxide moieties on the coordination mode of the ligands with Tb³⁺ and Eu³⁺ ions. The bridging imido-group facilitates the deprotonation of the imido- bis(phosphine oxide) ligand followed by the formation of tris-complexes. The spectral and PXRD analysis of the separated colloids indicates that the high stability of the tris-complexes provides their safe conversion into polystyrenesulfonate-stabilized colloids using the solvent exchange method. The red Eu³⁺-centered luminescence of the tris-complex exhibits the same specificity in the solutions and the colloids. The pronounced luminescent response on the antibiotic ceftriaxone allows for sensing the latter in aqueous solutions with an LOD value equal to 0.974 μM.

The present work introduces coordinative binding of Cu^II ions with both amino-functionalized silica nanoparticles (SNs) and green-emitting carbon dots (CDs) as the pregrequisite for the Cu^II-assisted self-assembly of the CDs at the surface of the SNs. The produced composite SNs exhibit stable in time stimuli-responsive green fluorescence derived from the Cu^II-assisted assemblage of CDs. The fluorescence response of the composite SNs is sensitive to the complex formation with glutathione (GSH), enabling them to detect it with the lower limit of detection of 0.15 μM. The spin-trap-facilitated electron spin resonance technique indicated that the composite SNs are capable of self-boosting generation of ROS due to Cu^II→Cu^I reduction by carbon in low oxidation states as a part of the CDs. The intensity of the ESR signals is enhanced under the heating to 38 °C. The intensity is suppressed at the GSH concentration of 0.35 mM but is enhanced at 1.0 mM of glutathione, while it is suppressed once more at the highest intracellular concentration level of GSH (10 mM). These tendencies reveal the concentrations optimal for the scavenger or reductive potential of GSH. Flow cytometry and fluorescence and confocal microscopy methods revealed efficient cell internalization of SNs-NH₂-Cu^II-CDs comparable with that of “free” CDs.

The present work introduces the series of thiacalix[4]arenes (H₄L) bearing different upper-rim substituents (R = H, Br, NO₂) for rational design of ligands providing an antenna-effect on the NIR Yb³⁺-centered luminescence of their Yb³⁺ complexes. The unusual inclusive self-assembly of H₃L⁻ (Br) through Br$\mathsf{\pi }$ interactions is revealed through single-crystal XRD analysis. Thermodynamically favorable formation of dimeric complexes [2Yb³⁺:2HL³⁻] leads to efficient sensitizing of the Yb³⁺ luminescence for H₄L (Br, NO₂), while poor sensitizing is observed for ligand H₄L (H). X-ray analysis of the single crystal separated from the basified DMF solutions of YbCl₃ and H₄L(NO₂) has revealed the transformation of the dimeric complexes into [4Yb³⁺:2L⁴⁻] ones with a cubane-like cluster structure. The luminescence characteristics of the complexes in the solutions reveal the peculiar antenna effect of H₄L(R = NO₂), where the triplet level at 567 nm (17,637 cm⁻¹) arisen from ILCT provides efficient sensitizing of the Yb³⁺ luminescence.