Switchable interfaces

Fig. 2 The signal-responsive membrane associated with an ITO electrode and coupled with the enzyme-based logic gates. (A) AFM topography images (10x10 pm ) of the membrane with the closed (a) and open (b) pores. (B) The electron transfer resistance, / et, of the switchable interface derived from the impedance spectroscopy measurements obtained upon different combinations of the input signals. The right and left bars correspond to the OR-Reset and AND-Reset systems, respectively. (Adapted from ref. 83, with permission Copyright American Chemical Society, 2009).

The above-described (see Section 18.6) polyvinylpyridine (PVP) brush functionalized with the Os(dmo-bpy)2Cl redox centers was used to generate the pH-switchable interface capable of mediating electron transport with enzymes only being in the ON state at pH < 4.5 [30]. Laccase is a well-known enzyme frequently... 

Light-Switchable Activation of Redox Proteins by Means of Photoisomerizable Command Interfaces Associated with Electrodes... 

Redox enzymes are the active component in many electrochemical enzyme electrode biosensor devices.1821 The integration of two different redox enzymes with an electrode support, in which one of the biocatalysts is photoswitchable between ON and OFF states, can establish a composite multisensor array. The biomaterial interface that includes the photoswitchable enzyme in the OFF state electrochemi-cally transduces the sensing event of the substrate corresponding to the nonphoto-switchable enzyme. Photochemical activation of the light-active enzyme leads to the full electrochemical response, corresponding to the analysis of the substrates of the two enzymes. As a result, the processing of the signals transduced by the composite biomaterial interface in the presence of the two substrates permits the assay of the... 

Switchable DNA interfaces for the highly sensitive detection of label-free DNA targets. Proceedings of the National Academy of Sciences of the United States of America, 104, 17364-17369. 

Meng, E, Zhang, X.,Xu, G.,Yong, Z., Chen, H., Chen, M., Li, Q., Zhu,Y, 2011. Carbon nanotube composite films with switchable transparency. ACS Appl. Mater. Interfaces 3, 658-661. 

As described in the first report, a 0.5- to 50-mg sample of wet (or frozen) sediment was placed in a quartz tube that was then placed in (he platinum coil of a pyrolysis probe. The probe was inserted into the cooled interface chamber of the reaction system, which was then purged with helium carrier gas. The interface chamber was heated to 250°C and the pyrolysis probe temperature ramp started. About 10% of the helium carrier stream was split off to a thermal conductivity-flame ionization detector series, which provided profiles of products evolved from the sample. The main portion of the helium carrier flow was directed via switchable multiport valves through a pair of Tenax traps for the appropriate time periods to trap the Pj and P2 groups of evolved organic materials. 

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