m-PTAS sensor calibration curve. The m-PTAS sensor outputs were calibrated against [Hb] measured by a reference hematology analyzer (ADVIA 2120i, Siemens AG, Germany). Sixteen blood samples of [Hb] ranging from 0.1 g/dL to 17.8 g/dL were analyzed (see Table S1 for detailed information). Each sample was measured ten times, and the error bar denotes 95% confidence interval (CI). The measurement was fitted with a Hill equation (R2 > 0.99). Curve fitting constants are given in Table S2.