Enzymatic sensing with organic electrochemical transistors

Abstract

Since their development in the 1980's organic electrochemical transistors (OECTs) have attracted a great deal of interest for biosensor applications. Coupled with the current proliferation of organic semiconductor technologies, these devices have the potential to revolutionize healthcare by making point-of-care and home-based medical diagnostics widely available. Unfortunately, their mechanism of operation is poorly understood, and this hinders further development of this important technology. In this paper glucose sensors based on OECTs and the redox enzyme glucose oxidase are investigated. Through appropriate scaling of the transfer characteristics at various glucose concentrations, a universal curve describing device operation is shown to exist. This result elucidates the underlying device physics and establishes a connection between sensor response and analyte concentration. This improved understanding paves the way for rational optimization of enzymatic sensors based on organic electrochemical transistors.

Fast-switching all-printed organic electrochemical transistors

“…Conversely, in the (EG)OFETs field-effect gating provide charge accumulation only along a thin sheet of the semiconducting layer. Printable or printed OECTs have been realized and reported previously for various applications, such as logic circuits [14], sensors [15,16] and active matrix addressed displays [17,18]. They typically suffer from non-symmetric switching characteristics, i.e.…”

Electrochemical transistors with ionic liquids for enzymatic sensing

“…The gate electrode, for example, can be used as a "working electrode", 40 and the current that flows in it as a result of a redox reaction can be amplified by the OECT. This amplification manifests itself by the fact that the sensor's sensitivity increases with gate voltage, 14 and leads to devices that require very simple electronics for signal readout. Zhu et al took advantage of 45 this fact to demonstrate a simple sensor for glucose in phosphate buffered saline (PBS).…”

“…9 The sensor consisted of a PEDOT:PSS OECT with a Pt gate electrode and with the redox enzyme glucose oxidase (GOx) dissolved in the electrolyte (PBS). This work was extended to demonstrate 50 sensors that work down to the micromolar concentration range, 14 can be made entirely out of polymers by using an appropriate mediator, 15 and operate with other redox enzymes, allowing the development of multianalyte sensors. 10 In In this communication, we report an enzymatic sensor based on an OECT that uses a RTIL as an integral part of its structure.…”

“…It should be noted that we found it critical to create such wells on both the channel and the gate electrode in order to achieve reproducible control over the spread of the solution. upon gating, 14 which has been understood on the basis of the reactions shown in Fig. 3.…”

Browsing the Real World using Organic Electronics, Si‐Chips, and a Human Touch

“…Dedicated printed sensors can measure the presence and concentration of various relevant compounds 4,5 . The sensor signals are then processed into data that is transmitted through an antenna or connector to devices for further data handling, and then possibly also transferred into the Internet cloud.…”