Crop seeds sold to farmers are often counterfeit, as are pharmaceuticals, banknotes and alcoholic beverages. Scientists at the Massachusetts Institute of Technology (MIT) have devised a way to spot fakes by attaching silk dots to real seeds.
The World Bank estimates that up to 50% of the seeds sold in some African countries are not actually from the reputable agricultural companies they claim to be. These fake seeds do not germinate as well as the better grown regular seeds and therefore yield much lower yields.
Researchers at MIT turned to biodegradable, food-safe silk microparticles for a way to verify the provenance of purported seeds. The scientist has designed his four different types of these particles. Each particle reflects light differently when placed in a liquid solution that then dries and crystallizes.
By mixing different types of particles in random combinations, concentrations and ratios and applying small dots of the mixed solution to seeds, product-specific tags with unique spectral signatures that are virtually impossible to replicate can be created. increase. Its signature can be read by a device such as a Raman spectrometer…certainly few farmers have this on hand.
With that limitation in mind, the researchers mixed four different colored salts with four types of silk microparticles. Doing so not only greatly increased the number of combinations, but also gave uniquely colored seed-applied dots that could be imaged with a smartphone camera equipped with a macro lens.
The idea is that an agricultural company would start by applying dots with one unique spectral signature to all seeds within a given batch. When a farmer purchases a bag of those seeds, he can read one of the seed dots on his smartphone and compare that signature code online with what the company has recorded for that batch. If the two match, the farmer knows the seed actually came from that company.
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The dots used in this study are only one-tenth of an inch (about 2.5 mm) in diameter. That said, when commercial scale use is more practical, a liquid solution containing microparticles can be easily applied as a whole-seed coating.
A paper on this study, led by Prof. Anantha Chandrakasan, Prof. Benedetto Marelli, postdoctoral researcher Hui Sun, and graduate student Saurav Maji, was recently published in a journal. scientific progress.
Source: MIT
