Discrimination of complex odors using a polymer modified graphene resistor array

The fabrication of a graphene chemical sensor array is detailed along with its performance against complex odors. The sensor consists of an array of graphene resistors fabricated on a single substrate with chemical diversity added to the resistors by overcoating them with organic polymers. The array consists of three polymers and one bare graphene resistor. We show the chemical diversity afforded by the addition of the polymer overcoatings provides complex sorption-based and electrical-based changes to the sensor array response. These two mechanisms are shown by complete reversal in resistance to the same analyte across the array. Sub-sampling the responses to create a feature vector and using linear discriminate analysis (LDA) and a feedforward neural network we were able to identify the analytes with 100% accuracy. Additionally, LDA plots show correlation between analytes with similar qualitative characteristics. These results demonstrate a graphene/polymer array sensor, applicable to compact, low-cost, low-power, and adaptable for chemical sensing needs.