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Published on: October 18, 2018
Pico-Molar Sensing of Reactive Oxygen Species Using Organic Field-Effect Transistors with Conjugated Polymer Layers
Minjae Kim1,2, Bongmo Kim1,2, Chulyeon Lee1,3
1Organic Nanoelectronics Laboratory and KNU Institute for Nanophotonics Applications (KINPA), School of Chemical Engineering and Applied Chemistry, Kyungpook National University, Daegu41566, Republic of Korea.
None:
Facile detection of reactive oxygen species (ROS) is crucial for early-stage diagnosis and disease prediction, including cancer. Here, it is demonstrated that quercetin (QCT), a naturally derived polyphenol, forms nanoscale aggregates (clusters) within the matrix of the conjugated polymer, poly(3-hexylthiophene) (P3HT), and acts as a key material for sensing ROS in organic field-effect transistors (OFETs). To investigate the influence of QCT loading, the QCT content was varied from 0 to 70 wt % in the 50 nm-thick P3HT:QCT sensing channel layers for OFETs. Morphological analysis revealed that submicron-size QCT aggregates (up to ∼600 nm) were formed in the P3HT:QCT films. The basic transistor test showed that the best performance could be achieved at QCT = 30 wt % (abbreviated as QCT30-OFET). In the perfusion test that enables steady-state flow of ROS solutions, QCT30-OFETs could detect a wide range of ROS concentrations from 20 pM to 1 mM. The QCT30-OFETs were able to detect ROS systematically even under consecutive repeated injections of ROS solutions. A simple drop test demonstrated that droplets of ROS solutions could be easily detected by the present QCT30-OFET sensors, supporting the effectiveness and practicability of the QCT-based ROS sensing concept.
