"Cancers can be very difficult to detect, even using sophisticated imaging techniques. Physicians often use biomarkers (proteins, DNA, or other things made by the body) in blood or urine to detect cancer, but many cancers do not produce biomarkers in high enough quantities, or even at all. Our team has designed nanoparticle-based 'synthetic biomarkers' that are injected, interact with the tumor, and create a signal in the urine. Using a test strip literally made of paper that works like a home pregnancy test and costs about 25 cents, we can detect these urinary biomarkers and diagnose cancer inexpensively and anywhere in the world. These images demonstrate how 'frugal engineering' can combine low-cost materials with sophisticated nanoscale techniques to enable inexpensive, point-of-care diagnosis of diseases that otherwise must be identified using costly and skill-intensive techniques that are unavailable in places like the developing world."