New method for label-free electrical DNA detection

For sensor applications, a more interesting parameter is the degree of change in the average ion concentration in the intermolecular spaces upon the hybridization event. The model for the theoretical calculations of the average concentration of cations and 

Electrochemical Sensors, Biosensors and Their Biomedical Applications 

FIGURE 7.6 Cell model for the theoretical calculations of the DNA hybridization-induced ion-concentration redistribution as well as the average concentration of cations and anions in the intermolecu-lar spaces. Both the ssDNA and dsDNA have been modeled as negatively charged cylinders with a radius = 0.5 nm and = 1 nm, respectively, which form a hexagonal lattice with a cell radius of R the DNA molecules are arranged normal to surface of the FED with a center-to-center average separation distance of = 2R n r) is the ion concentration as a function of the coordinate r from the DNA axis and tiq is the bulk-ion concentration. 

For the above-described model, the average concentration of cations and ainons in the intermolecular spaces can be calculated using equations derived in [51]  

b is the distance between the nearest unit charges along the cylinder (b = 

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