MIT engineers have designed a new nanoparticle sensor that could enable early diagnosis of cancer with a simple urine test. The sensors, which can detect many different cancerous proteins, could also be used to distinguish the type of a tumor or how it is responding to treatment. The nanoparticles are designed so that when they encounter a tumor, they shed short sequences of DNA that are excreted in the urine. Analyzing these DNA “barcodes” can reveal distinguishing features of a particular patient’s tumor. The researchers designed their test so that…