Love wave sensors with silver-modified polypyrrole nanoparticles are developed in this work. These systems prove functional at room temperature with enhanced response, sensitivity and response time, as compared to other state-of-the-art surface acoustic wave (SAW) sensors, towards volatile organic compounds (VOCs). Results demonstrate the monitoring of hundreds of ppb of compounds such as acetone, ethanol and toluene with low estimated limits of detection (~3 ppb for acetone). These results are attributed to the use of silver-modified polypyrrole as a second guiding/sensitive layer in the Love wave sensor structure, which provides further chemically active sites for the gas-solid interactions. The sensing of low VOCs concentrations by micro sensing elements as those presented here could be beneficial in future systems for air quality control, food quality control or disease diagnosis via exhaled breath as the limits of detection obtained are within those required in these applications.
Keywords: polypyrrole; gas sensors; love wave sensors; volatile organic compounds
This research was funded by the Czech Science Foundation (GAČR) via Grant No. 20-20123S, the Spanish Ministry of Economy and Competitiveness via projects TEC2015-74329-JIN-(AEI/FEDER, EU), and TEC2016-79898-C6-1-R (AEI/FEDER, EU) and by Universidad Nacional Autónoma de México via Grant DGAPA-UNAM-PAPIIT TA100118. The support of the “Ramón y Cajal” programme is also acknowledged. This research has made use of the infrastructures the Spanish ICTS Network MICRONANOFABS, partially supported by MINECO, and Czech CEITEC Nano Research Infrastructure, supported by MEYS (2016-2019).