Monday, 25 November 2013
The Romans Have Been Hailed as Pioneers of Nanotechnology
A lot of the monuments of Classical civilisation stand as testament to the ingenuity and sophistication of ancient people, which still captivates us with a sense of awe to this day. Just think of the Colosseum in Rome or the Parthenon in Athens. Either of which would be sensational if built today, let alone being constructed centuries ago. Sometimes though, it is not the largest monuments, but small artifacts that can astound us - and in this case the sophisticated design goes all the way to a nanoscopic level!
This Roman glass cup dates back to the fourth century A. D. and today resides in the British Museum. It is known as the Lycurgus Cup, depicting King Lycurgus of Thrace being ensnared in the grasp of tangling grapevines for incurring the wrath of Dionysus, the god of revelry and wine. It is a detailed work of art in its own right and would have been a valuable prestige gift between or from Roman elites. My seriously, it appears jade green when lit from the front, but when illuminated from behind it appears crimson.
When a some tiny broken chips were found and sent away to researchers they could not believe what they found. When viewed through a microscope it was realised that the glass was embedded with a fine peppering of metal grains. The glass contained particles of gold and silver around 50 nanometres in diameter spread evenly through the glass. To put that size into perspective, that is less than one thousandth the size of a grain of ordinary table salt that you might have in the saltshaker on your kitchen table! The change in colour is caused by electrons in the metal grains vibrating when hit by light, and the angle on which the observer sees this.
The chalice was far too valuable to be experimented on, so to further research it's properties a plastic plate was embedded with tiny wells containing glass embedded with a nanomixture of gold and silver grains of a comparable size to those found in the Lycurgus Cup. The researchers found that these wells changed colour depending on the different solutions contained, turning green when containing water and red when containing oil. It also produced a range of colour changes indicating whether a solution was sugar or salt based. Amazingly this prototype based off an ancient wine cup was more than a 100 times more sensitive to saline levels in solution than current commercial techniques!
I wonder if, it may also have been used originally to detect poison in drinks. Many early poisons were either relatively local plant extracts that tended to colour water (but may not have been as easily seen in wine) or were salt-based and easily added to an unguarded cup at say a feast. There is a well known set of special porcelain in Topkapi Palace in Istanbul, which reportedly was specially acquired by the Ottoman Sultans because of its ability to change colour in reaction to poisons contained in food or drink. Whether the Lycurgus Cup was intended to actually detect poisons...or even sold on this as a false pretence I cannot say, although it is a tantalising thought.
Remarkably this 1600 year old cup has shown that the Romans were effectively pioneering nanotechnology by deliberately employing techniques that would produce this glass. This (re-)discovery may pave the way for future highly sensitive kits or sensors that could detect drugs or pathogens in bodily fluids, or detect dangerous liquids at checkpoints, borders or airports. Interesting isn't it, how the investigation of an ancient artifact can reveal unexpectedly modern applications.
To read more about the Lycurgus Cup, see: