Ultrasensitive detection of hazardous reactive oxygen species using flexible organic transistors with polyphenol-embedded conjugated polymer sensing layers.

•Flexible OFETs with the polyphenol-embedded conjugated polymers are fabricated.•Rutin-based OFETs can quickly detect superoxide at extremely low concentrations.•The OFET sensors exhibit outstanding durability upon repeated and reuse tests.•Superoxide generated in the macrophages can be effectively detected by the OFETs.