Detection of Volatile Compounds Emitted by Bacteria in Wounds Using Gas Sensors.

In this paper we analyze an experiment for the use of low-cost gas sensors intended to detect bacteria in wounds using a non-intrusive technique. Seven different genera/species of microbes tend to be present in most wound infections. Detection of these bacteria usually requires sample and laboratory testing which is costly, inconvenient and time-consuming. The validation processes for these sensors with nineteen types of microbes (1 , 2 , 6 , 1 , 1 , 2 and 6 ) are presented here, in which four sensors were evaluated: TGS-826 used for ammonia and amines, MQ-3 used for alcohol detection, MQ-135 for CO₂ and MQ-138 for acetone detection. Validation was undertaken by studying the behavior of the sensors at different distances and gas concentrations. Preliminary results with liquid cultures of 10⁸ CFU/mL and solid cultures of 10⁸ CFU/cm of the 6 strains revealed that the four gas sensors showed a response at a height of 5 mm. The ammonia detection response of the TGS-826 to showed the highest responses for the experimental samples over the background signals, with a difference between the values ​​of up to 60 units in the solid samples and the most consistent and constant values. This could suggest that this sensor is a good detector of , and the recording made of its values ​​could be indicative of the detection of this species. All the species revealed similar CO₂ emission and a high response rate with acetone for , and .