Constructing a Nanopipette-Based DNA Electromechanical Device.

Solid-state nanopore and nanopipette sensors are powerful devices for the detection, quantification, and structural analysis of biopolymers such as DNA and proteins, especially in carrier-enhanced resistive-pulse sensing. However, hundreds of different molecules typically need to be sampled from solution and analyzed to obtain statistically robust information. This limits the applicability of such sensors and complicates associated workflows. Here, we present a new strategy to trap DNA structures in the sensing region of a nanopipette through end functionalization and nanoparticle capping. We develop a robust set of descriptors to characterize the insertion and presence of nanoparticle-DNA constructs in the nanopipette tip and show that they remain mobile and responsive to external electric fields over extended periods of time. This is for repeated readout of the same DNA structure and could enable new applications for such sensors, for example, in flow and in confined environments.