Label-free detection of Cordyceps sinensis using dual-gate nanoribbon-based ion-sensitive field-effect transistor biosensor

We report a dual-gate nanoribbon-based ion-sensitive field-effect transistor (NR-ISFET) biosensor system for direct label-free detection of Cordyceps sinensis's DNA (CorDNA) by conductance measurements of the NR-ISFET biosensors, where sample delivery can be conducted by a cavity or microchannel. Compared with conventional methods, the NR-ISFET biosensors demonstrate smaller sample amount and shorter detection time. Especially the measurements in a microchannel at dual-gate (DG) mode exhibit a better sensitivity of 0.5054 mS/dec in a wide dynamic range spanning four orders of magnitude, a lower limit of detection (LOD) of 50 pM, and significantly improved specificity as compared to these with single solution-gate (SG). Moreover, the performance of the NR-ISFET biosensor system can be improved in a microchannel in comparison with a cavity, which may be attributed to better surface modification in a microchannel with larger DNA probe density on the sensing surface.