Enzymes 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... 

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... 

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