Integration of Ordered Mesoporous Carbon Spheres-Based Ion-Sensitive Electrodes With Flexible Organic Field-Effect Transistors for Multiplexed Ion Sensing

In the path toward the integration of flexible organic field-effect transistors (OFETs) into the construction of manufactured-on-demand ion sensors, it is still challenging to obtain high stability and sensitivity as required by high detection accuracy, especially for a multisensing system. In this work, ordered mesoporous carbon (OMC) spheres with high surface area and superhydrophobicity were synthesized and introduced as ion-to-electron transducer layer to improve the sensitivity and stability of Na $^{+}$ and $\text{K}^{+}$ ion-sensitive electrodes (ISEs). High-performance low-voltage (< 3 V) operated ion-sensitive OFETs (ISOFETs) were further fabricated by on-chip low-temperature packaging of the developed ISEs and OFETs. A three-channel multiplexed flexible sensing tag with improved detection accuracy was demonstrated in a handheld circuit readout system. This ISOFET sensor has great potential in multiplexed sensing systems and will significantly improve efficiency and accuracy in the field of biochemical analysis.