It may sound like something straight out of the crime-drama CSI, but scientists in Brazil and the US are developing a method of identifying “fingerprints” on banknotes in order to spot counterfeits.
The process is done using what chemists call a “mass spectrometric technique” that can detect the authenticity of a banknote in seconds.
This technique allows analysts to recognize the chemical makeup of the banknote by identifying individual structures of the note’s particular molecules.
The “fingerprint” is determined by conducting tests on the molecules. By vaporizing a sample, and breaking the sample down into ions with the help of a laser beam, distinct patterns emerge in the mass-to-charge (m/z) ratio of the particles. Studies of authentic banknotes will reveal that multiple samples contain the same m/z ratios, while fake banknotes reveal a different set of distinct markets that is noticeably different.
Obviously, this is not a security feature that the average citizen will be able to employ, but researchers say this mode of identification could help speed up investigations at forensic laboratories that are bogged down with increasing forgery cases. Though this process sounds complex, the identification of a fake note using the mass
spectrometric technique only takes seconds.
In addition to being used to detect counterfeited currency, Brazilian researchers are working together with the Brazilian Federal Police and banknote manufacturers to find ways of adding unique chemical signatures to bills, either as an ink splotch, an invisible stamp, or a bar code.