Healthcare Monitoring Sensors Based on Organic Transistors: Surface/Interface Strategy and Performance

Abstract

Organic transistors possess inherent advantages such as flexibility, biocompatibility, customizable chemical structures, solution‐processability, and amplifying capabilities, making them highly promising for portable healthcare sensor applications. Through convenient and diverse modifications at the material and device surfaces or interfaces, organic transistors allow for a wide range of sensor applications spanning from chemical and biological to physical sensing. In this comprehensive review, we focus on the surface and interface engineering aspect associated with four types of typical healthcare sensors. We systematically analyze and highlight the device operation principles, sensing mechanisms, and particularly focus on surface/interface functionalization strategies that contribute to the enhancement of sensing performance. An outlook and perspective on the critical issues and challenges in the field of healthcare sensing using organic transistors are provided as well.This article is protected by copyright. All rights reserved

Review of recent advances and sensing mechanisms in solid-state organic thin-film transistor (OTFT) sensors

“…65 OTFT-based sensors are promising candidates for health monitoring and diagnostic tools owing to their non-invasive nature and ability to be designed to achieve high sensitivity and selectivity with sensing elements that contain bio-specific recognition elements. 30 A number of recent reviews provide an excellent overview of efforts to develop wearable and flexible biosensors for point-of-care health monitoring and medicine including different device architectures and target analytes. 30,66–69 In a recent perspective, Tsuyoshi Minami and coworkers described chemical sensing platforms based on OTFTs functionalized with artificial receptors, in which the gate electrode is extended to serve as an active material (Fig.…”

“…30 A number of recent reviews provide an excellent overview of efforts to develop wearable and flexible biosensors for point-of-care health monitoring and medicine including different device architectures and target analytes. 30,66–69 In a recent perspective, Tsuyoshi Minami and coworkers described chemical sensing platforms based on OTFTs functionalized with artificial receptors, in which the gate electrode is extended to serve as an active material (Fig. 3A).…”

“…176 Organic semiconductors, owing to their structural similarity to proteins, carbohydrates and nucleic acids, and their stretchability similar to human tissues, have potential to be used as biocompatible materials. 177 Recent reviews have been published on biocompatible material-based wearable and implantable biosensors by Liu et al 178 and L. Ma et al 179 while studies on surface and interfacial engineering of these devices have been summarized in a review by Jiang et al 30 There are some preliminary biocompatibility studies on organic semiconductors which could provide a foundation for sensor development. One method for quantifying the biocompatibility of organic semiconductors for OTFTs in health monitoring is by performing cell viability studies where the percentage of cells which can absorb neutral dyes are measured to quantitatively determine the number of live cells over time while in contact with the device active layer.…”

“…Reviews of OTFT-based sensors have been published in recent years which discuss active materials, thin-film engineering, fabrication techniques and applications including as gas sensors and as diagnostic tools in healthcare. 17,26–30 In this review, we aim to survey and summarize recent advances in the understanding of sensing mechanisms, as well as the fabrication and application of the second type of sensor, solid-state OTFT sensors. Section 2 will discuss mechanisms of response such as oxidation and reduction, doping and physical responses of OTFTs due to environmental analytes.…”

Organic Mixed Ionic–Electronic Conductors Based on Tunable and Functional Poly(3,4-ethylenedioxythiophene) Copolymers

“…Similarly, an OMIEC used in regenerative medicine applications would benefit from cell adhesion sites that promote cell integration and proliferation . In sensing applications such as biomolecule or electrochemical detection where an OECT device configuration plays a role, surface engineering is applied to prevent nonspecific binding and enhance the selectivity and specificity of the sensor . Post-functionalization of the conjugated polymer rather than its precursor monomer is favorable owing to the large size of biological molecules, such as proteins, that can impede the polymerization process.…”