Sensitivity of point defects in one dimensional nanocircuits

When tailored to contain a single resistive defect, one dimensional nanocircuits can realize high dynamic range, high bandwidth transduction of single molecule chemical events. The physical mechanisms behind this sensitive transduction, however, remain poorly understood. Here, we complement ongoing sensing measurements with scanning probe characterization of the electronic properties of defects. The high sensitivity of defect sites is directly probed, and is found to be in excellent agreement with a finite element model containing realistic device parameters for the defect sites. The model illuminates the most likely sensing mechanisms of these single molecule circuits, and fully supports the premise that further tailoring of the defect sites could enable the chemically selective interrogation of a wide range of complex molecular interactions.