When stuff gets really small, weird things happen. At less than two billionths of a metre across – ten thousand times smaller than the width of a human hair – tiny particles of gold have some very strange properties. Known as quantum dots, they absorb certain types of light and convert it into heat. Researchers are harnessing these distinctive characteristics by embedding gold quantum dots inside a solid shell, trapping larger gold particles inside like a child's rattle. Tests in mice suggest that these 'quantum rattles' could help doctors see cancers within the body, or even shrink tumours. On the right is an image of a single rattle taken using a high-powered electron microscope, with the gold specks showing up as white blobs. Taking this as his inspiration, artist Jaap Scheeren created a giant rattle (left), with the help of some gold balloons, making the quantum world visible to our eyes
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.