Organic Photo‐Electrochemical Transistor‐Based Biosensor: A Proof‐of‐Concept Study toward Highly Sensitive DNA Detection

• Published in: Advanced healthcare materials 2018-10, Vol.7 (19), p.e1800536-n/a
• Main Authors: Song, Jiajun, Lin, Peng, Ruan, Yi‐Fan, Zhao, Wei‐Wei, Wei, Weiwei, Hu, Jin, Ke, Shanming, Zeng, Xierong, Xu, Jing‐Juan, Chen, Hong‐Yuan, Ren, Wei, Yan, Feng
• Format: Article
• Language: English
• Subjects: Biocompatibility; Biosensors; Cadmium sulfide; Charge transfer; Deoxyribonucleic acid; DNA; DNA sensors; Electrochemistry; Electrodes; exciton–plasmon interaction; Fabrication; Gold; Nanoparticles; organic electrochemical transistors; organic photo‐electrochemical transistors; Photosensitivity; photo‐electrochemical sensors; Quantum dots; Transistors
• ISSN: 2192-2640; 2192-2659
• DOI: 10.1002/adhm.201800536

Organic bioelectronics have shown promising applications for various sensing purposes due to their significant advantages in term of high flexibility, portability, easy fabrication, and biocompatibility. Here, a new type of organic device, organic photo‐electrochemical transistor (OPECT), is reported, which is the combination of an organic electrochemical transistor and a photo‐electrochemical gate electrode modified with CdS quantum dots (QDs). Thanks to the inherent amplification function of the transistor, the OPECT‐based biosensor exhibits much higher sensitivity than that of a traditional biosensor. The sensing mechanism of the OPECT is attributed to the charge transfer between the photosensitive semiconductor CdS QDs and the gate electrode. In an OPECT‐based DNA sensor, target DNA is labeled with Au nanoparticles (NPs) and captured on the gate electrode, which can influence the charge transfer on the gate caused by the exciton–plasmon interactions between CdS QDs and Au NPs. Consequently, a highly sensitive and selective DNA sensor with a detection limit of around 1 × 10−15 m is realized. It is expected that OPECTs can be developed as a high‐performance platform for numerous biological detections in the future. A novel organic photo‐electrochemical transistor (OPECT) is realized based on the combination of an organic electrochemical transistor and a photo‐electrochemical gate electrode. Due to the inherent amplification function of the transistor, a highly sensitive and selective OPECT‐based DNA sensor is obtained, which shows a detection limit of 1 × 10−15 m. The OPECT is expected to have promising applications in various bioanalyses.