Researchers achive real time detection of low gas concentrations

Researchers achieve real-time detection of low gas concentrations
 https://www.sciencedaily.com/releases/2025/01/250109125523.htm
  Allowing gas detection and identification in just seconds,
  approach using a coherent control strategy offers promise for
  real-time monitoring in environmental, health and industrial applications
Source:
 Optica
Summary:
Researchers have developed a method for quickly detecting and identifying
 very low concentrations of gases, which, could form the basis for highly
 sensitive real-time sensors for applications such as environmental monitoring,
 breath analysis and chemical process control.

Interesting method to stop a quartz tuning fork

All that said, my MQ type gas sensors work fine:
 https://www.tinytronics.nl/nl/sensoren/lucht/gas
but those are not so narrow band...