Transducer nanometric

These results illustrate how extended supramolecular-polymolecular entities build up through molecular recognition directed polyassociation of complementary components. They also show that molecular chirality is transduced into supramolecular helicity, which is expressed at the level of the material on nanometric and micrometric scales, amounting to a sort of size amplification of chirality. 

There are basically three broad categories of approaches towards nanobiosensors and in particular in electrochemical nanobiosensor development. The modification of a (macroscopic) transducer with nanomaterials is the first of these approaches. In electrochemical biosensors, this would translate into large electrodes modified with nanomaterials. The second approach is the miniaturization of the transducer, namely the use of nanoelectrodes [307] or other miniaturized circuitry of nanometric dimensions. The modification of biomolecules with nanomaterials or coupling of biomolecules and nanomaterials is the third category of approach towards nanobiosensors. Of course the lines between these approaches are blurred and some sensor designs may draw from more than one of these concepts. 

The conceptual theme of hierarchically stractured materials that are specifically designed to maximize anode or cathode performance can be separately considered in the following components (1) the bulk electrode materials, (2) pores in the bulk material that accommodate fluid flow, (3) mesoporous or structural material to transition from the bulk material to the nanometric dimensions, (4) the nanostmctured transducer, (5) the bio-nano interface, and (6) the biocatalyst (Figure 10.1) [23]. All of the elements must be coupled to achieve electron flow from the electron donor through the architecture to the final electron acceptor. In the anodic half-cell, fuel is oxidized and the liberated electrons are transferred to the electrode and through an external load. The cathode provides the BFC with electromotive force by catalyzing the reduction of oxygen at relatively positive potentials. 

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