Mold testing and lab reports are all very fine, but one of the latest mold detecting technology has been around for a very long time.
Dogs.
Dogs can detect mold by scent better than we can; they have more than 200 million scent receptors (as compared to our 5 million) and the wetness of a dog’s nose helps the scent dissolve and disperse. Twelve percent of a dog’s brain is dedicated to scent (though this does vary according to breed) as apposed to one percent in humans.
See a mold dog in action.