Renewable point of care (POC) sensors provide a new solution for rapid detection of disease biomarkers, but these devices face the challenge of repeated contamination during cyclic use, making it difficult to achieve both high sensitivity and excellent cycle times, which hinders the rapid development of this field.

 Zhang Fengjiao, associate professor of the University of Chinese Academy of Sciences, Di Chong'an, researcher of the University of Chinese Academy of Sciences/Institute of Chemistry of the Chinese Academy of Sciences, and Li Jia, associate chief physician of the General Hospital of the Chinese People's Liberation Army reported that they proposed a new way of building a drug molecule probe mediated electromechanical chemical transistor (DM-OECT). The device has a highly sensitive detection capability for blood epidermal growth factor (EGFR) in blood, and has a unique renewable function, providing a new idea for low-cost preparation of POC sensors.

POC sensors can achieve rapid detection of disease biomarkers, which is an important path for the diagnosis and treatment of major diseases and postoperative rehabilitation monitoring. It is also one of the important development directions of bioelectronics. However, existing POC sensors generally have high costs, and specific diseases require long-term high-frequency detection, which brings huge economic burdens to high-risk populations. The core feature of renewable POC sensors is the use of a single device to achieve multiple sensitive detections of biomarkers, thereby significantly reducing usage costs. The traditional regeneration method involves pH regulation, heating, or voltage induction to dissociate the probe from the analyte. However, thermodynamic equilibrium and reversible adsorption can cause repeated surface contamination, leading to a rapid decrease in sensitivity of the device during cyclic use. The use of physical or chemical etching methods can avoid material residue, but it can damage the active layer and limit the increase in the number of device cycles.

In this work, researchers proposed a novel drug molecule probe mediated organic electrochemical transistor sensor (DM-OECT) concept. This device has a new mechanism of "refresh in sensing (RIS)", which means that the device achieves synchronous regeneration during the detection process of the test substance. Researchers use gefitinib drug molecules as probes, utilizing the charge transfer between gefitinib and organic semiconductors, the specific targeting effect between gefitinib and EGFR, and the conformational flipping of EGFR gefitinib to achieve high-sensitivity sensing of EGFR and functional surface regeneration during the sensing process.

Source: Sensor Expert Network