A model for nanomechanical behavior of microcantilever-ssDNA chip induced by electrostatic repulsion

The paper is devoted to study of the influence of screened electrostatic repulsion on nanomechanical behavior of microcantilever-DNA chip during the grafting process. First, Zhang's two-variable method for laminated cantilevers and the sphere-chain model for single-stranded DNA (ssDNA) are combined to formulate a four-layered energy model for ssDNA chip systems. Second, the influence of grafting density, ssDNA chain length on immobilization deflection is investigated by the minimum principle of energy and the cell method in Monte Carlo (MC) simulation. Numerical predictive tendency at high salt concentration is similar to those observed in some related experiments on ssDNA chips.