Platinum(IV) complexation with the nitrate ion in aqueous solutions according to 195Pt, 15N, 14N, and 17O NMR data

Solutions of platinum(IV) nitrate were studied by ¹⁹⁵Pt, ¹⁵N, ¹⁴N, and ¹⁷O NMR and IR and Raman spectroscopy. It was found that in nitric acid, two interrelated systems of nitrate complexes, mono- and polynuclear ones, coexist. The complexes predominating in concentrated solutions are [Pt₂(μ-OH)(μ-NO₃)(NO₃)₂(H₂O)_{6 ? x} (OH) _x ]^{(4 ? x)+}, [Pt₄(μ-OH)₃(μ-NO₃)₃(NO₃)₃(H₂O)_{9 ? x} (OH) _x ]^{(7 ? x)+}, [Pt4(μ-OH)₄(μ-NO₃)₂(NO₃)₄(H₂O)_{8 ? x} (OH) _x ]^{(6 ? x)+}, and [Pt₄(μ-OH)₆(NO₃)₃(H₂O)_{16 ? x} (OH) _x ]^{(7 ? x)+}.     

Bionanoconjugates of tyrosinase and peptide-derivatised gold nanoparticles for biosensing of phenolic compounds

Bionanoconjugates of the enzyme tyrosinase (TYR) and gold nanoparticles (AuNPs) functionalised with a peptide (CALNN) were produced in solution and characterised. The formation of stable TYR–AuNP:CALNN bionanoconjugates (BNCs) was supported by a decrease of the surface charge of the BNCs as determined by ζ-potential and an increase in hydrodynamic diameter as determined by Dynamic Light Scattering (DLS). UV/Vis studies of pH-induced aggregation revealed distinct protonation patterns for the BNCs when compared with AuNP:CALNN alone, further substantiating BNC formation. Activity studies of the BNCs for the reduction of di-phenols in solution indicated that TYR not only remains active after conjugation, but interestingly its activity in the BNCs is higher than for the free enzyme. In conclusion, AuNP:CALNN can provide a suitable platform for the immobilisation of TYR, leading to BNCs with increased enzyme activity and a wider pH working range, with promising uses in electrochemical biosensors for the detection of mono- and di-phenolic compounds.     

Biocompatibility and Degradation of Porous Matrixes from Lactide and ε-Caprolactone Copolymers Formed in a Supercritical Carbon Dioxide Medium

Cytotoxicity and in vitro degradation rate of porous matrices based on lactide and ε-caprolactone copolymers formed via supercritical foaming are determined. A high biocompatibility of materials obtained by the above method is demonstrated.     

Effect of phosphonic and carboxylic acids on crystallization of sparingly soluble salts

The mechanism of the action of phosphonic and carboxylic acids on the nucleation and crystal growth of carbonates has been studied under sedimentation-simulating conditions.     

Gas-tight proton-conducting Nd2 − xCaxZr2O7 − δ (x = 0, 0.05) ceramics

Journal of Solid State Electrochemistry - Gas-tight Nd2 − xCaxZr2O7 − δ (x = 0, 0.05) pyrochlore materials have been prepared via...     

Stabilization of cooling water-circulation systems with organophosphorus compounds

Effect of organophosphorus compounds on stability parameters of cooling water-circulation systems was studied using a laboratory setup simulating sedimentation processes under dynamic conditions. It was found that introduction of organophosphates reduces the sedimentation rate by a factor of 2.5–3.5 as compared with a model system containing no inhibitors due to the activation of growth of the less stable polymorphic modification of calcium carbonate.