3D Z-scheme conjugated polymer/CuO for organic photoelectrochemical transistor bioassay.

Organic photoelectrochemical transistor (OPECT) is an emerging technology studying photo-electric-biological recognition events. Here, this work reports the three-dimensional (3D) Z-scheme poly (1,4-diethynylbenzene) (pDEB)@CuO heterojunction as a high-efficacy photogating module and its application for OPECT bioassay. Specifically, 3D Z-scheme pDEB@CuO heterojunction enabled fast charge transport and ion diffusion in the system, achieving remarkable amplification capability with a current gain as high as ca. 9.6 × 10. By linking with GOx-labeled sandwich immunorecognition, the impact of GOx-generated HO on the OPECT made possible the sensitive bioassay. Exemplified by carcinoembryonic antigen (CEA) as the model target, the OPECT device achieved a linear detection range spanning from 100 fg/mL to 100 ng/mL and coupled with a detection limit as low as 72 fg/mL. This work provided a generic and extensible platform for the designation of novel bioassay systems.