DNA-decorated carbon nanotubes for chemical sensing

TL;DR

This paper introduces a novel nanoscale chemical sensor using DNA-coated carbon nanotubes that can detect various gases rapidly, reversibly, and with sequence-specific responses, suitable for electronic nose and tongue applications.

Contribution

It presents a new sensor platform combining ss-DNA with carbon nanotube FETs, enabling selective, rapid, and reusable gas detection with tunable responses.

Findings

Sensors respond to gases not detectable by bare nanotubes

Responses vary with DNA sequence, allowing selectivity

Sensors exhibit rapid response and recovery, maintaining stability over cycles

Abstract

We demonstrate a new, versatile class of nanoscale chemical sensors based on single-stranded DNA (ss-DNA) as the chemical sensors recognition site and single-walled carbon nanotube field effect transistors (swCN-FET) as the electronic read-out component. swCN-FETs with a nanoscale coating of ss-DNA respond to gas odors that do not cause a detectable conductivity change in bare devices. Responses of ss-DNA/swCN-FETs differ in sign and magnitude for different gases, and can be tuned by choosing the base sequence of the ss-DNA. ss-DNA/swCN-FET sensors detect a variety of odors, with rapid response and recovery times on the scale of seconds. The sensor surface is self-regenerating: samples maintain a constant response with no need for sensor refreshing through at least 50 gas exposure cycles. This very remarkable set of attributes makes sensors based on ss-DNA decorated nanotubes very promising for "electronic nose" and "electronic tongue" applications ranging from homeland security to disease diagnosis.