Practical Chemical Sensors from Chemically Derived Graphene

TLDR

Recent literature on carbon nanotube and graphene sensors informs the discussion of these results. The study develops chemical sensors from chemically converted graphene dispersions via spin coating to produce single‑layer films on interdigitated electrode arrays. Graphene dispersions are prepared from graphite oxide in anhydrous hydrazine, spin‑coated into single‑layer films on interdigitated electrodes, and mounted on a micro hot plate substrate to monitor temperature dependence. The sensors detect NO₂, NH₃, and 2,4‑dinitrotoluene with linear, ohmic I–V curves, and their response follows a charge‑transfer mechanism with minimal contact influence.

Abstract

We report the development of useful chemical sensors from chemically converted graphene dispersions using spin coating to create single-layer films on interdigitated electrode arrays. Dispersions of graphene in anhydrous hydrazine are formed from graphite oxide. Preliminary results are presented on the detection of NO2, NH3, and 2,4-dinitrotoluene using this simple and scalable fabrication method for practical devices. Current versus voltage curves are linear and ohmic in all cases, studied independent of metal electrode or presence of analytes. The sensor response is consistent with a charge transfer mechanism between the analyte and graphene with a limited role of the electrical contacts. A micro hot plate sensor substrate is also used to monitor the temperature dependence of the response to nitrogen dioxide. The results are discussed in light of recent literature on carbon nanotube and graphene sensors.