Charge-Transfer Mechanism for Cytochrome c Adsorbed on Nanometer Thick Films. Distinguishing Frictional Control from Conformational Gating
摘要:
Using nanometer thick tunneling barriers with specifically attached cytochrome c, the electron-transfer rate constant was studied as a function of the SAM composition (alkane versus terthiophene), the omega-terminating group type (pyridine, imidazole, nitrile), and the solution viscosity. At large electrode-reactant separations, the pyridine terminated alkanethiols exhibit an exponential decline of the rate constant with increasing electron-transfer distance. At short separations, a plateau behavior, analogous to systems involving -COOH terminal groups to which cytochrome c can be attached electrostatically, is observed. The dependence of the rate constant in the plateau region on system properties is investigated. The rate constant is insensitive to the mode of attachment to the surface but displays a significant viscosity dependence, change with spacer composition (alkane versus terthiophene), and nature of the solvent (H2O versus D2O). Based on these findings and others, the conclusion is drawn that the charge-transfer rate constant at short distance is determined by polarization relaxation processes in the structure, rather than the electron tunneling probability or large-amplitude conformational rearrangement (gating). The transition in reaction mechanism with distance reflects a gradual transition between the tunneling and frictional mechanisms. This conclusion is consistent with data from a number of other sources as well.
Charge-Transfer Mechanism for Cytochrome c Adsorbed on Nanometer Thick Films. Distinguishing Frictional Control from Conformational Gating
摘要:
Using nanometer thick tunneling barriers with specifically attached cytochrome c, the electron-transfer rate constant was studied as a function of the SAM composition (alkane versus terthiophene), the omega-terminating group type (pyridine, imidazole, nitrile), and the solution viscosity. At large electrode-reactant separations, the pyridine terminated alkanethiols exhibit an exponential decline of the rate constant with increasing electron-transfer distance. At short separations, a plateau behavior, analogous to systems involving -COOH terminal groups to which cytochrome c can be attached electrostatically, is observed. The dependence of the rate constant in the plateau region on system properties is investigated. The rate constant is insensitive to the mode of attachment to the surface but displays a significant viscosity dependence, change with spacer composition (alkane versus terthiophene), and nature of the solvent (H2O versus D2O). Based on these findings and others, the conclusion is drawn that the charge-transfer rate constant at short distance is determined by polarization relaxation processes in the structure, rather than the electron tunneling probability or large-amplitude conformational rearrangement (gating). The transition in reaction mechanism with distance reflects a gradual transition between the tunneling and frictional mechanisms. This conclusion is consistent with data from a number of other sources as well.
A method of producing a polymer part comprising the following steps: (a) incorporating a hydrophobic small molecule into the polymer before, during or after manufacture of the polymer part, the hydrophobic small molecule and the polymer being essentially inert to one another; and (b) annealing the polymer part to induce migration of the hydrophobic small molecules to a surface of the polymer part to provide that surface with a specified degree of hydrophobicity defined by the combination of the polymer and the hydrophobic small molecule; is described. Polymer parts made according to the method are also described.
Method of producing a polymer part and polymer part
申请人:STRATEC CONSUMABLES GmbH
公开号:US10611890B2
公开(公告)日:2020-04-07
A method of producing a polymer part comprising the following steps: (a) incorporating a hydrophobic small molecule into the polymer before, during or after manufacture of the polymer part, the hydrophobic small molecule and the polymer being essentially inert to one another; and (b) annealing the polymer part to induce migration of the hydrophobic small molecules to a surface of the polymer part to provide that surface with a specified degree of hydrophobicity defined by the combination of the polymer and the hydrophobic small molecule; is described. Polymer parts made according to the method are also described.
A plurality of polymer slides, each having a polymer part with a first polymer surface portion uncoated and a second surface portion coated with a metal. The first and second surface portions each have different surface coating properties and have respective first and second specified degrees of hydrophobicity which are different from each other. A hydrophobic small molecule is located in the polymer part of each polymer slide, and the hydrophobic small molecule and the polymer are essentially inert to one another. Adjacent polymer slides are arranged in a manner that the first polymer surface of one slide faces a metal coated second surface portion of another slide. The hydrophobic small molecule evaporates from said first polymer surface portion of the polymer part of one polymer slide onto the adjacent metal coated second surface portion of another polymer slide.
Immunsensorischer Wandler und Verfahren zu seiner Herstellung
申请人:F. HOFFMANN-LA ROCHE AG
公开号:EP0485874B1
公开(公告)日:1995-09-20
DRUG DELIVERY FROM IMPLANTS USING SELF-ASSEMBLED MONOLAYERS-THERAPEUTIC SAMS
申请人:Agrawal C. Mauli
公开号:US20090123516A1
公开(公告)日:2009-05-14
Disclosed are medical devices comprising one or more surfaces, one or more SAM molecules attached to the one or more surfaces of the medical device, and one or more therapeutic agents attached to the one or more self-assembled monolayer molecules. Also disclosed are medical devices comprising one or more surfaces, one or more self-assembled monolayer molecules attached to the one or more surfaces of the medical device, one or more linkers comprising a first functional group and a second functional group, the first functional group attached to the self-assembled monolayer molecule and a therapeutic agent attached to the second functional group. The therapeutic agent may be attached to the SAM molecule via a linker. The present invention also concerns methods of administering a therapeutic agent to a subject, comprising contacting the subject with one of the medical devices set forth herein.