An Inexpensive, Single Use Carbon-Based Sensor for the Rapid and Early Detection of Hydrocarbon Leaks.

A novel fabrication process for a single use, low-cost organic solvent sensor has been developed. The process is simple, and the materials are readily available. Carbon nanomaterials are self-assembled at a water/hexane interface, where the hexane phase contains dissolved paraffin wax. Upon the controlled evaporation of hexane, the paraffin wax precipitates, trapping the carbon nanoparticles at the surface in a paraffin wax backbone, realizing a carbon-nanoparticle-decorated film. The film is hydrophobic and highly electrically conductive. When exposed to hydrocarbons or a mixture of hydrocarbons, the conductive carbon network deteriorates and an increase in film resistivity is monitored. The rate of change in resistivity is proportional to the concentration and composition of organic molecules in contact with the film.