It is noteworthy that the real-time measurement of our FIA assay can quickly identify abnormal sampling. For example, in Fig. , sample #5 was unusually viscous and became pinned to the injection hole. The absence of signal allowed us to quickly identify the failure and resolve it by testing at a later stage, without interrupting the analysis workflow. In summary, our low-cost two-electrode cartridge demonstrated accurate high-throughput testing of urine samples in a clinical scenario.