Three million times smaller than an expectant crowd, these tiny needles of black silicon are nevertheless waiting for something. Surface-enhanced Raman spectroscopy (SERS) is a common technique used to spot harmful substances, looking for tell-tale chemical fingerprints in potentially carcinogenic or even explosive samples. But this is only possible after the mystery molecules have attached to a microscopic platform, or substrate. There’s a problem though, many substrates used in SERS react in some way with the chemicals they grab on to, clouding accurate analysis. Black silicon is inert – it doesn’t react with chemical samples, making it ideal as a substrate. Pictured here using scanning electron microscopy, its crystalline prongs are just waiting to grab onto something dangerous.
Written by John Ankers
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