Nanowire Field Effect Transistors have emerged as a promising technology for point-of-care application. However, their application as quantitative sensors has not been well explored. In this work we propose a calibration scheme for multiplexed nanoribbon field effect sensors by utilizing the initial current rate rather than the end point detection. A linear response of nanosensors is observed in medically relevant range of analyte concentration. Moreover, we are able to show that top-down fabrication technique yields reproducible result and devices with uniform electrical characteristics. In addition, we demonstrate that device calibration can be done by using either baseline current or device transconductance normalization.