Is there a way I can determine if someone in the supply chain has tampered with them such that they can be remotely detonated?

In the recent pager detonations I believe it was determined that Pentaerythritol tetranitrate (PETN) was inside the pagers. I haven't heard the same about walkie talkies, but I'm cautiously assuming the mechanism was similar

According to that wikipedia page on PETN[1]:

> Both parcels in the 2010 cargo plane bomb plot were x-rayed without the bombs being spotted. Qatar Airways said the PETN bomb "could not be detected by x-ray screening or trained sniffer dogs". The Bundeskriminalamt received copies of the Dubai x-rays, and an investigator said German staff would not have identified the bomb either. New airport security procedures followed in the U.S., largely to protect against PETN.

If these are undetectable by dogs, is there any method to detect explosive chemicals, such as detection strips, that are available to consumers?

[1]: https://en.wikipedia.org/wiki/Pentaerythritol_tetranitrate