Organic Bioelectronic Devices for Metabolite Sensing

Abstract

Electrochemical detection of metabolites is essential for early diagnosis and continuous monitoring of a variety of health conditions. This review focuses on organic electronic material-based metabolite sensors and highlights their potential to tackle critical challenges associated with metabolite detection. We provide an overview of the distinct classes of organic electronic materials and biorecognition units used in metabolite sensors, explain the different detection strategies developed to date, and identify the advantages and drawbacks of each technology. We then benchmark state-of-the-art organic electronic metabolite sensors by categorizing them based on their application area (in vitro, bodyinterfaced, in vivo, and cell-interfaced). Finally, we share our perspective on using organic bioelectronic materials for metabolite sensing and address the current challenges for the devices and progress to come. CONTENTS 1. Introduction 4581 2. Metabolite Sensing in the Body at a Glance 4583 2.1. Metabolite Sensing and Signaling Mechanisms: Sensor−Transducer−Effector Model 4583 2.2. (Biological) Recognition Units 4584 3. Organic Electronic Materials in Metabolite Sensing 4588 3.1. Graphene 4588 3.2. Carbon Nanotubes 4590 3.3. Conjugated Polymers (CPs) 4590 3.4. Composite Materials 4591 4. Sensing Methods 4592 4.1. Electrodes 4593 4.1.1.

Cyano‐Functionalized n‐Type Polymer with High Electron Mobility for High‐Performance Organic Electrochemical Transistors

“…Organic electrochemical transistors (OECTs), as an important application of organic mixed ionic-electronic conductors (OMIECs), have received increasing attention in recent years. [1][2][3][4][5] Owing to the ionic-electronic coupling characteristic of OMIECs, OECTs can effectively transduce small ionic/electrical input signals into large electrical output signals, [6,7] making them particularly useful in developing organic bioelectronics such as biochemical sensing, [8][9][10] electrophysiological signal recording, [11][12][13][14] cell impedance monitoring, [15,16] neuromorphic computing, [17][18][19][20] as well as low-voltage amplifiers and circuits. [21][22][23] In OECT operation, the input signal is used as gate voltage to control the ion uptake from electrolyte into its channel, changing its channel conductance by ion-induced bulk doping.…”

Operation Mechanism of n‐Type Organic Electronic Metabolite Sensors

“…One conjugated polymer‐based device, the organic electrochemical transistor (OECT), has become particularly popular for detecting metabolites via enzymatic reactions occurring in the electrolyte surrounding the film. [ 16 ] The OECT is an amplifying transducer that uses a conjugated polymer in the channel (between the source and the drain contacts), and sometimes as a coating on the gate electrode. The gate and the channel are immersed in the electrolyte and connected by a common source electrode.…”

Nanomaterials‐assisted metabolic analysis toward in vitro diagnostics

“…It also presents adaptability into assays of POCT due to the intrinsic merits of portability, easy operation, and low cost. [ 38,39 ] Electrochemical sensor measures the targeted metabolite molecules through current, resistance, and voltage variations within the electrodes. As a critical component in an electrochemical system, electrodes produce electric signal outputs by interacting with the targeted analytes.…”