Ask HN: Innovative ideas in security domain ?

I plan to design an explosive detector which will cost below $200 and will be able to detect explosives in a Car or Person in less than 6 seconds. Assuming that I succeed in doing so do you think such an equipment will be a hit? Especially in countries like India where very mall, multiplex has metal detectors, personal frisking etc? What other devices do you possibly think of that can help me make money?