In a discovery with applications ranging from hair dyeing to electronic sensors to development of materials with improved properties, scientists are reporting the first synthesis of gold nanoparticles inside human hairs. Their study appears in ACS’ journal Nano Letters. Philippe Walter and colleagues explain that gold nanoparticles -- 40,000-60,000 of which could fit across the width of a human hair -- are a hot topic. Scientists are exploring uses, ranging from electronics and sensors to medical diagnostic tests and cancer treatments. Gold nanoparticles have been deposited on hair for use as electrodes, and gold nanoparticles had been used to dye wool. Walter’s team looked at a new use -- dyeing hair, inspired by the ancient Greeks’ and Romans’ use of another metal, lead, to color their hair.
