Invisible nanoparticle barcodes could help law enforcement catch criminals

An invisible barcode is being developed to track explosives, medicines and bank notes, scientists report. A team from the Worcester Polytechnic Institute in the US has found that some nanoparticles have unique characteristics that can be used to mark items. The researchers say the technique could link objects to their manufacturer, seller or buyer. The study is published in the journal Scientific Reports. “Nanoparticles are so small, they can be put into any objects,” said Dr Ming Su, who carried out the research. Using barcodes to mark and trace objects is now used widely by manufacturers. But the researchers say that covert barcodes could be used to fight crime and reduce counterfeiting. The team have found that some nanoparticles can be added to items such as explosives, ink and medicines during the manufacturing process. Because these particles have a unique melting point that can be detected with scanners, they provide a “thermal” barcode.