I can understand how filtration systems would help, both particle and activated charcoal, similar to what is used for chem and biowarfare. The trick with filters is to ensure they get replaced when required / before they are too contaminated to function correctly.
What is unclear to me is how one might make a general purpose "cabin fumes sensor" as there are hardly any universal detection methods. The common ones for CO and some combustible gasses each require entirely different surface chemistries and processing to make the detection. I suppose one could find a sensor for a particular sort of chemical that is used on the plane, but there is a reason there aren't robots replacing sniffer dogs any time soon. And if that chemical is partly combusted then one would need sensors for each of the possible combustion products. Perhaps it's time to reintroduce canaries into the working environment.