A team of researchers from the University of South Australia (UniSA), the University of Adelaide, and the University of New South Wales may have found a solution to increasingly sophisticated methods used for counterfeiting.
The team has found a promising anti-counterfeiting measure through high density imaging that uses phosphorus nanocrystals to create fluorescent images.
UniSA Research Fellow at the Future Industries Institute, Dr Nicolas Riesen has found that exposing certain inorganic nanocrystals to ultraviolet (UV) light will activate the nanocrystals, essentially turning on their fluorescent properties. When those nanocrystals are exposed to blue light, the regions that have been activated by the UV light will emit red fluorescent light.
The technique presents an exciting opportunity for anti-counterfeiting measures, particularly for those in finance and health – two highly lucrative and, in the case of medicine, dangerous global counterfeiting markets. The World Health Organization (WHO) estimates that as much as 10% of the global pharmaceutical market – a halftrillion- dollar marketplace – is counterfeit. The Reserve Bank of Australia typically receives around 30,000 counterfeits every year, at a rate of approximately 15 counterfeits per million genuine banknotes, with an estimated value of AU$1–2 million.
Dr Riesen said this new method could cost-effectively be used to place small images on banknotes or medical packaging that would be extremely difficult to forge and would be readable with a basic microscope and blue light. It could also be used for putting a stamp on consumer products, for anti-counterfeiting purposes.