Differentiation of Complex Vapor Mixtures Using Versatile DNA-Carbon Nanotube Chemical Sensor Arrays

TL;DR

This paper presents a scalable DNA-functionalized carbon nanotube sensor array capable of highly reproducible detection and discrimination of complex vapor mixtures, including structural isomers and human-related VOCs.

Contribution

It introduces a reproducible fabrication method for DNA-NT sensors that can distinguish similar molecules and complex vapor mixtures, advancing vapor sensing technology.

Findings

Sensors are highly reproducible and follow equilibrium thermodynamics.

Able to detect target analytes amidst volatile interferents.

Discriminates between structural isomers, enantiomers, and complex VOC mixtures.

Abstract

Vapor sensors based on functionalized carbon nanotubes (NTs) have shown great promise, with high sensitivity conferred by the reduced dimensionality and exceptional electronic properties of the NT. Critical challenges in the development of NT-based sensor arrays for chemical detection include the demonstration of reproducible fabrication methods and functionalization schemes that provide high chemical diversity to the resulting sensors. Here, we outline a scalable approach to fabricating arrays of vapor sensors consisting of NT field effect transistors functionalized with single-stranded DNA (DNA-NT). DNA-NT sensors were highly reproducible, with responses that could be described through equilibrium thermodynamics. Target analytes were detected even in large backgrounds of volatile interferents. DNA-NT sensors were able to discriminate between highly similar molecules, including structural isomers and enantiomers. The sensors were also able to detect subtle variations in complex vapors, including mixtures of structural isomers and mixtures of many volatile organic compounds characteristic of humans.