Molecular resistors

Molecular Resistor Organic molecules to achieve resistor type of behavior are as shown below in Fig. 3. 

Most of the experiments for detecting charged macromolecules with FEDs, reported in literature, have been realized using a transistor structure [11-36], Recent successful experiments on the detection of charged biomolecules as well as polyelectrolytes with other types of FEDs, namely semiconductor thin him resistors [39 11], capacitive MIS [42] and EIS structures [43-50], have demonstrated the potential of these structures - more simple in layout, easy, and cost effective in fabrication - for studying the molecular interactions at the solid-liquid interface. A summary of results for the DNA detection with different types of FEDs is given in Table 7.1. 

Finally, we mention a novel transduction concept based on the heal evolved from a reaction such as combustion. Microcalorimetric devices can now be made using lithographic techniques. One of the two sensitive areas of such a device (were evolved heat can be measured) was coated with a thin film of CoA1P04-5, the other was kept open as a reference 135] The additional benefit of a zeolite with catalytic activity for such a device is the molecular sieving effect that can be combined in the response of the sensor (a molecule too big to enter the catalytically active interior of the zeolite should only show a weak response). The change in temperature was measured with a meandering Pt-wire resistor. This device was examined in the detection of CO and cyclohexane, and sensitivity and selectivity in the low ppm-range was observed. 

In order to reduce the size of integrated circuits, the technologies used to fabricate them have been continuously changing. As circuit features approach the nanometer scale, it has been proposed that devices (diodes, transistors, resistors, capacitors, and conductive tracks) could be made from molecules with suitable properties, instead of patterned doped silicon layers [65]. For that purpose, it is essential to characterize their electronic properties at the level of single molecules, and the molecular junction methods described above offer many advantages to do it. 

It has been suggested by Winfield [29] that cytochrome c is an example of a molecular integrated circuit and as such should contain input and output terminals, variable resistors, an electron trap, and a one way electron valve . The impedance matching capability at both terminals are then necessary characteristics of this circuit. Winfield has further characterized the tryptophan ring as a major part of a resonating system. 

Graph potentials, a new class of atomic invariants defined as the solutions of a system of linear equations, were proposed as an efficient method of atom partitioning. Molecular graph potentials were developed by analogy with an electrical network, where resistors of the network correspond to chemical bonds and the network nodes correspond to atoms, To cause the flow of electrical current in the network, an additional node is introduced and connected with all other nodes of the network by edges containing resistors and current sources. Atom potentials are computed as the roots of the following system of linear equations ... 

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