Chemically diverse sensor arrays based on electrochemically copolymerized pyrrole and styrene derivatives

Abstract

Chemically diverse sensor arrays were synthesized directly on interdigitated array electrodes by electrodepositing copolymers of pyrrole and substituted styrene monomers. By selecting a range of substituted styrenes and controlling deposition conditions (growth potentials) it was possible to create a wide range of chemical variations, resulting in differential partitioning and in turn differential sensor responses. The effectiveness of the electrochemical copolymerization deposition was investigated with FT-IR spectroscopy to determine the relative amounts of co-monomer and the morphology of the films was studied with SEM. The impact of composition on film sensitivity was explored by determining changes in response (e.g., changes in resistance) of sensors to various odorants as a function of degree of functionalization. Performance of the chemically diverse arrays was determined using statistical analysis of response patterns which demonstrate the chemical diversity capable of differentiating different odorants can be achieved with this approach. Figures of merit including reproducibility, sensitivity and selectivity were determined. This report represents a significant advancement in the use of electronically conducting polymers in sensor array technology by moving past the limited number of conducting polymer monomers. The ease by which diversity can be imparted during electrodeposition makes this approach ideal for use in integrated circuit technology, allowing deposition on chip microstructures without the need for additional lithographic steps.