Analysis of recognition of fructose by imprinted polymers

Binding of fructose to the fructose imprinted polymer (MIP(Frc)) and pinacol imprinted polymer (control) were studied both in batch and a flow through mode. The influence of the cross-linkers ethylene glycol dimethacrylate (EDMA) and trimethylolpropane trimethacrylate (TRIM) on the binding characteristics was analysed. TRIM cross-linked MIPs showed a lower (unspecific) binding for the control polymer (pinacol imprinted) and higher binding of fructose as compared with the EDMA-MIPs. Furthermore interactions of a TRIM cross-linked molecularly imprinted polymer against fructose and its corresponding template were studied using a thermistor. Label-free detection of fructose was realised in the range of 0.5-10mM. The difference in enthalpy changes between specific binding of fructose to boronic acid moieties of the MIP and non-specific binding to the matrix leads to an 18-fold higher apparent imprinting factor than batch binding studies. Cross-reactivity studies using MIP sensor indicate that the interaction of fructose to MIP generates higher signal than disaccharides. The studies described in this paper demonstrate the potential of direct characterisation of molecular binding events.     

Controllable formation of nanoscale patterns on TiO2 by conductive-AFM nanolithography

We report on the nanopatterning of double-bond-terminated silane (5-hexenyltrichlorosilane, HTCS) molecules on titania (TiO2) using conductive atomic force microscopy (AFM). The influences of tip electrostatic potential and scanning velocity, relative humidity and of the repeated application of voltage on the topographic height, width, and hydrophilic and hydrophobic contrast of the resultant patterns were investigated. Tip voltage and tip velocity ( v) were applied between -10 V 相似文献   

Novel beta-lactam antibiotics synthesized by amination of catechols using fungal laccase

Novel cephalosporins, penicillins, and carbacephems were synthesized by amination of catechols with amino-beta-lactams like cefadroxil, amoxicillin, ampicillin and the structurally related carbacephem loracarbef using laccase from Trametes sp. All isolated monoaminated products inhibited the growth of several Gram positive bacterial strains in the agar diffusion assay, among them methicillin-resistant Staphylococcus aureus strains and vancomycin-resistant Enterococci. Observed differences in the cytotoxicity and in vivo activity in a "Staphylococcus-infected, immune suppressed mouse" model are discussed.     

[BuN(CH2CH2)3NBu]3[Pb5I16] · 4 DMF – ein Iodoplumbat mit nahezu D5h‐symmetrischem Anion

[BuN(CH₂CH₂)₃NBu]₃[Pb₅I₁₆] · 4 DMF – an Iodoplumbate Anion with approximately D _5h Symmetry The star‐shaped anion of [BuN(CH₂CH₂)₃NBu]₃‐[Pb₅I₁₆] · 4 DMF ( 1 ) consists of a cyclic arrangement of five PbI₆ octahedra sharing one common I atom in the centre of an almost planar Pb₅ ring. Compound 1 crystallizes in space group P2₁ with a = 1657.2(1), b = 2029.2(1), c = 1773.6(1) pm, β = 113.238(8)°, Z = 2.     

Polymere Iodoplumbate – Synthese und Kristallstrukturen von (Pr3N–C2H4–NPr3)[Pb6I14(dmf)2] · 4 DMF, (Pr3N–C2H4–NPr3)[Pb(dmf)6][Pb5I14] · DMF und (Me3N–C2H4–NMe3)2[Pb2I7]I

Polymeric Iodoplumbates – Synthesis and Crystal Structures of (Pr₃N–C₂H₄–NPr₃)[Pb₆I₁₄(dmf)₂] · 4 DMF, (Pr₃N–C₂H₄–NPr₃)[Pb(dmf)₆][Pb₅I₁₄] · DMF, and (Me₃N–C₂H₄–NMe₃)₂[Pb₂I₇]I (Pr₃N–C₂H₄–NPr₃)[Pb₆I₁₄(dmf)₂] · 4 DMF ( 1 ) and (Pr₃N–C₂H₄–NPr₃)[Pb(dmf)₆][Pb₅I₁₄] · DMF ( 2 ) have almost the same composition, but completely different structures. Both compounds are formed selectively depending on the reaction and crystallization conditions. In 2 the Pb^II atoms are coordinated either by six bridging I^– ligands in the two-dimensional [Pb₅I₁₄]^4– network or by six DMF ligands in the [Pb(dmf)₆]²⁺ cations. In contrast, (Me₃N–C₂H₄–NMe₃)₂[Pb₂I₇]I ( 3 ) contains non-coordinating I^– anions between the iodoplumbate layers. The iodoplumbate anions in 2 and 3 consist of face and corner sharing PbI₆ octahedra, whereas in 1 PbI₆ and PbI₅(dmf) octahedra share common edges to form a one-dimensional polymeric section of the PbI₂ structure. (Pr₃N–C₂H₄–NPr₃)[Pb₆I₁₄(dmf)₂] · 4 DMF ( 1 ): Space group P1, a = 920.1(3), b = 1597.2(5), c = 1613.9(4) pm, α = 66.02(2), β = 84.53(2), γ = 85.99(2)°, V = 2156(1) · 10⁶ pm³; (Pr₃N–C₂H₄–NPr₃)[Pb(dmf)₆][Pb₅I₁₄]·DMF ( 2 ): Space group P2₁, a = 1201.21(9), b = 3031.1(2), c = 1294.96(9) pm, β = 108.935(7)°, V = 4459.8(5) · 10⁶ pm³; (Me₃N–C₂H₄–NMe₃)₂[Pb₂I₇]I ( 3 ): Space group Pnma, a = 2349.9(2), b = 1623.83(9), c = 980.75(7) pm, V = 3742.4(5) · 10⁶ pm³.     

Synthesis and stabilizing properties of amphipolar polyelectrolytes

The European Physical Journal E - A series of well-defined amphipolar block, graft and statistical copolymers based on the same polar and non-polar monomers were synthesized and investigated for...     

Iodoplumbate mit vier‐ und fünffach koordinierten Pb2+‐Ionen

Iodoplumbates with Tetra‐ and Penta‐coordinated Pb²⁺ Ions In contrast to all known iodoplumbates with octahedrally coordinated Pb²⁺ ions, square pyramidal geometry is observed in the iodoplumbate chains of (Pr₄N)[PbI₃] ( 1 ) and [Mg(dmf)₆][PbI₃]₂ ( 2 ), whereas the isolated anions in (Ph₄P)₂[Pb₂I₆] ( 3 ) and [Bu₃N–(CH₂)₃–NBu₃][PbI₄] ( 4 ) contain tetra‐coordinated lead atoms. (Pr₄N)[PbI₃] ( 1 ): a = 910.86(6), b = 1221.46(7), c = 1907.7(1) pm, V = 2122.5(2) · 10⁶ pm³, space group P2₁2₁2₁; [Mg(dmf)₆][PbI₃]₂ ( 2 ): a = 891.24(9), b = 1025.34(7), c = 1234.82(9) pm, α = 92.938(8), β = 106.457(8), γ = 98.100(7)°, V = 1066.4(2) · 10⁶ pm³, space group P1; (Ph₄P)₂[Pb₂I₆] ( 3 ): a = 1174.5(1), b = 722.29(7), c = 3104.8(4) pm, β = 100.50(1)°, V = 2589.8(5) · 10⁶ pm³, space group P2₁/n; [Bu₃N–(CH₂)₃–NBu₃][PbI₄] ( 4 ): a = 2178.3(1), b = 1008.63(5), c = 1888.3(1) pm, β = 110.003(5)°, V = 3898.6(4) · 10⁶ pm³, space group P2/c.