Aptamer Functionalized Zinc Oxide Field Effect Transistors For Odor Detection

Odor detection and identification are complex processes, and tasks that currently only animals do well. There is a pressing need for an electronic nose, or eNose, with good sensitivity, selectivity, and speed that mimics that ability. Food quality control operations, environmental sensing, occupational safety, and the defense sectors all require systems that can rapidly and reliably detect trace levels of volatile organic compounds. The goal of this work is to create a biologically inspired device which can accurately detect and identify odors at concentrations consistent with the most sensitive biological systems.In order to mimic a natural olfactory system, we replaced the biological components of the olfactory system with synthetic components. If successful, this approach would provide a basis for a computational strategy that identifies odor based on combinatorial patterns of receptor activation, so that the number of recognizable odors exceeds the number of receptors.Our efforts produced an aptamer-decorated zinc oxide field effect transistor (Apta-FET) that shows great sensitivity to target compounds, but limited selectivity. We demonstrated that aptamers attached to a FET respond to targets in a concentration-dependent manner, and that this response can be measured electrically. The limited selectivity of our device highlights the need for many different kinds of aptamers within the same device, as well as the need for more advanced computational analysis of the output data. It is our hope that these hurdles will be overcome.