An Oligonucleotide Sensor with Parallel Electrical Pathways

Abstract

Point-of-care sensors can combat the spread of infectious diseases and inform timely treatments. But in order to be used in this capacity, point-of-care sensors need to combine rapid detection speed with high sensitivity. Detection speed has traditionally been reduced by increasing the sensing surface area of the device, but this can increase noise and reduce sensitivity. In this work we align multiple tube-in-a-tube (Tube^2) nanostructures across a trench between two electrodes. Each Tube^2 consists of a semiconducting carbon nanotube nested within an outer nanotube densely functionalized with oligonucleotide probes. This device design provides a high surface area, while forcing the electrical current through distinct electrical pathways, allowing the binding events to be sensitively detected. Using this device architecture, we demonstrate the selective detection of Lyme disease oligonucleotide biomarkers in physiological ionic strength conditions on the order of seconds.