Wearable Fiber-Based Organic Electrochemical Transistors as a Platform for Highly Sensitive Dopamine Monitoring

Abstract

Fiber-based organic electrochemical transistors (FECTs) provide a new platform for the realization of an ultrafast and ultrasensitive biosensor, especially for the wearable dopamine (DA)-monitoring device. Here, we presented a fully filament-integrated fabric, it exhibited remarkable mechanical compatibility with the human body, and the minimum sensing unit was an organic electrochemical transistor (OECT) based on PVA-co-PE nanofibers (NFs) and polypyrrole (PPy) nanofiber network. The introduction of NFs notably increased the specific surface area and hydrophilicity of the PA6 filament, resulting in the formation of a large area of intertwined PPy nanofiber network. The electrical performance of PPy nanofiber network-modified fibers improved considerably. For the common FECTs, the typical on/off ratio was up to two orders of magnitude, and the temporal recovery time between on and off states was shortened to 0.34 s. Meanwhile, the device exhibited continuous cycling stability. In addition, the performances of FECT-based dopamine sensors depending on different gate electrodes have also been investigated. The PPy/NFs/PA6 filament-based dopamine sensor was more superior to the gold and platinum (Pt) wires, and the sensor presented long-term sensitivity with a detection region from 1 nM to 1 μM, rapid response time to a set of DA concentrations, remarkable selectivity in the presence of sodium chloride, uric acid, ascorbic acid and glucose, and superior reproducibility. Moreover, it could also be woven into the fabric product. The novel and wearable FECT device shows the potential to become the state-of-the-art DA-monitoring platform.

Rapid prototyping of 3D Organic Electrochemical Transistors by composite photocurable resin

“…However, the OECT operation consists of an electronic transduction (by the active channel) of ionic signals associated to some reactions at the gate electrode/electrolyte interface (as in the case of DA and Pt electrodes) and/or capacitive effects (Electrical Double layer formation). In the former case, the efficiency of such transduction often requires a specific functionalization aimed at amplifying the charge transfer mechanisms at the metallic gate/liquid electrolyte interface, hence LoDs comparable to the lowest DA concentrations determined by CV measurements can only be achieved upon functionalizing the Pt gate electrode 43 , 51 .…”

Semiconducting Small Molecules as Active Materials for p‐Type Accumulation Mode Organic Electrochemical Transistors

“…Organic electrochemical transistors (OECTs), as depicted schematically in Figure , have been widely explored for interfacing organic electronics with biologically and medically relevant systems. [ 1,2 ] The burgeoning field of organic bioelectronics has seen OECTs employed in a wide range of applications from neural interface devices for epileptogenic centers, [ 3 ] to biological analyte detection, [ 4–7 ] cardiac monitoring, [ 8 ] whole cell interface monitoring, [ 9,10 ] pH sensing, [ 11 ] in ion pumps, [ 12 ] and electronic plants. [ 13 ] While OECTs traditionally have comprised the conducting polymer mixture poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), semiconducting polymers have more recently been implemented as the active material in OECTs.…”

Organic Electrochemical Transistors as an Emerging Platform for Bio-Sensing Applications: A Review

“…Dopamine (DA) level detection in extracellular fluids or biological systems with excellent sensitivity, selectivity and fast response is of vital importance. Recently, Qing et al [93] have developed a fiber-based OECT fully integrated in fabric for DA sensing. The OECT was based on polyamide fibers (PA6) coated with PVA-co-PE nanofibers (NFs)/polypyrrole (PPy) nanofiber network [88].This device unit can be directly integrated into a plain weave fabric product by traditional loom (Figure 20c).…”

“…a) OECT sensor system directly integrated on cloth for selective detection of adrenaline (reproduced from[92] with permission from the Royal Society of Chemistry, Copyright © 2014), b) Schematic of the cotton-based OECT with Pt-gate electrode and an adrenaline molecule in its sensing process (reproduced from[92] with permission from the Royal Society of Chemistry, Copyright © 2014), c) (up) Preparation process and weaving of the fibers. Polypyrrole (PPy) is insitu polymerized onto the polyamide (PA6) fibers coated with PVA-co-PE nanofibers (NFs) and (down) assembly of the woven OECTs as wearable DA sensor (reproduced from[93] with permission from the American Chemical Society, Copyright © 2019), d) Screen-printed OECTs fabricated with two different geometries: G1 and (reproduced from G2[94] with permission from Springer Nature, Copyright © 2016).…”