Forensic investigation of criminal activity, including money counterfeiting and the trafficking and use of drugs and explosives, is set to become easier.
Newly developed invisible barcodes based on the unique thermal properties of nanoparticles offer a stealthy way of tagging trading objects so that they can more readily be tracked and traced.
The issue with visible barcodes is that they can be altered or duplicated. Invisible molecular and chemical tags that are currently in use aren’t suitable for large-scale labelling for a number of reasons. But the new barcode system, described in the journal Scientific Reports, may overcome these issues. It uses a panel of nanoparticles, identified by their discrete melting temperatures, to tag relevant objects. They can then be forensically traced to their manufacturer, vendor or purchaser.
The researchers suggest several uses of nanoparticle barcodes:
- Drug authentication. They can be added to solid and liquid drugs, where they remain stable and seem to have no appreciable toxic effects.
- Tracing the origins of explosives. Dinitrotoluene, a precursor to TNT, is tagged and the thermal signatures detected in the debris after detonation.
- Anti-counterfeiting. Selected nanoparticles are added to ink and polymers used in printing.