Dual‐Mode Sensing Chips for Wide‐Range and High‐Accuracy Biomarker Detection

Abstract As widely used commercial sensors, amperometric biosensors based on electrochemical (EC) reactions exhibit good linearity and reproducibility but suffer from a low dynamic range and poor limit of detection (LoD). In contrast, biosensors utilizing field‐effect transistors (FETs) demonstrate a wide detection range and ultralow LoDs but are susceptible to interferences or ionic strength influences and have poor quantitative accuracy due to their nonlinear response mechanism. Here, EC and carbon nanotube (CNT) FET‐based biosensors are integrated into one chip via a compatible fabrication process. The dual‐mode biosensing chip (DMSC) provides the advantages from both the EC biosensors and FET biosensors; these advantages include high reliability and accuracy for quantitatively detecting glucose, a dynamic detection range spanning 6 orders of magnitude, and a detection limit of 1 fM. The introduction of a time‐division multiplexing detection method enables the DMSC to carry out complementary detection of the same target, providing early warning of specific abnormal biomarkers and accurate determination of their concentration in real time. The DMSC approach is generally applicable to the detection of other biomarkers and provides exciting opportunities for more accurate self‐monitoring diagnostics in real situations.