Human tear fluids contain many proteins, metabolites, and other molecules whose concentrations change significantly with certain diseases. A research team has now developed a handy test kit for tears that can identify patients with jaundice. Their success is based on a hybrid sensor that simultaneously removes impurities from the sample. This approach could provide new methods for early detection and diagnosis based on complex bodily fluids, as the team reported in the journal Angewandte Chemie International Edition.