Ultrasensitive, universal single-ion nanodetector

TL;DR

This paper introduces a highly sensitive, universal single-ion detector based on carbon nanotubes that can detect any ion type in real-time by observing significant current changes in a CNT field-effect transistor.

Contribution

It presents a novel CNT-based ion sensor capable of universal detection without functionalization, with demonstrated high sensitivity to single ions.

Findings

Single ion detection causes a 5-order magnitude current increase.

The sensor operates as a resonant tunneling diode during ion detection.

The device can monitor ions continuously in real-time.

Abstract

In this paper, a carbon nanotube (CNT) based single-ion detector is proposed and its performance is evaluated with atomistic quantum transport models. The sensor can detect any ion type without molecule-specific functionalization and allows for continuous real-time ion monitoring. A single ion temporarily changes the operating principle of the sensor's CNT field-effect transistor into a resonant tunneling diode. The concrete device example of this paper showed a source-drain current increase of 5 orders of magnitude induced by a single ion.