Loynachan and colleagues have just published in September 2019 the paper entitled “Renal clearable catalytic gold nanoclusters for in vivo disease monitoring” in the journal Nature Nanotechnology. The authors report the synthesis of ~2 nm catalytic gold nanoclusters modified with protease substrates that respond to disease-related enzymes. The probe can be filtered through the kidneys and excreted into the urine as a facile disease indicator based on a colorimetric readout. The paper focuses on matrix metalloproteinase-responsive gold nanoclusters in an in vivo colorectal cancer mouse. This technology can be extended to the detection of several other disease-associated proteases offering the promise to democratize sensitive diagnostics in a low-resource setting.