A small, portable gas chromatograph (GC) was assembled for the trace detection of controlled substances using a novel quartz crystal microbalance sensor (QCM). The QCM crystal surface was modified with a variety of sorption materials to increase adsorption thereby amplifying mass detection. Single polymer thin film coatings increased the QCM response by 1-2 orders of magnitude, while operating at over 100°C. Adding a layer of carbonaceous nanomaterial (graphene or carbon nanotubes) above such a film dramatically increased sensitivity by up to 3 orders of magnitude compared to uncoated crystals. Separation and detection of sub-microgram quantities of controlled substances was carried out within minutes by employing a GC column and detector temperature ramp up to 220˚C. An additional 10-fold enhancement in sensitivity was achieved by mechanical abrasion of the sample swabs used in the sample introduction process. This study demonstrated a novel use of a polymer composite modified QCM as a chemical sensor at high temperatures.
https://carbonnanotubestech.com/wp-content/uploads/2015/01/pubs_acs_org_doi_pdf_10_1021_ac504101a.png 211 350 Matthew Yonan http://carbonnanotubestech.com/wp-content/uploads/2015/01/carbon-nanotube-tech-logo-300x40.jpg Matthew Yonan2015-01-28 03:29:342015-01-30 03:32:09High Temperature Mass Detection Using a Carbon Nanotube Bilayer Modified Quartz Crystal Microbalance as a Gas Chromatograph