Synthesis and electropolymerization of a perylenebisimide-functionalized 3,4-ethylenedioxythiophene (EDOT) derivative

"Clickable" Organic Electrochemical Transistors

Interfacing the surface of an organic semiconductor with biological elements is a central quest when it comes to the development of efficient organic bioelectronic devices. Here, we present the first example of "clickable" organic electrochemical transistors (OECTs). The synthesis and characterization of an azide-derivatized EDOT monomer (azidomethyl-EDOT, EDOT-N₃) are reported, as well as its deposition on Au-interdigitated electrodes through electropolymerization to yield PEDOT-N₃-OECTs. The electropolymerization protocol allows for a straightforward and reliable tuning of the characteristics of the OECTs, yielding transistors with lower threshold voltages than PEDOT-based state-of-the-art devices and maximum transconductance voltage values close to 0 V, a key feature for the development of efficient organic bioelectronic devices. Subsequently, the azide moieties are employed to click alkyne-bearing molecules such as redox probes and biorecognition elements. The clicking of an alkyne-modified PEG₄-biotin allows for the use of the avidin-biotin interactions to efficiently generate bioconstructs with proteins and enzymes. In addition, a dibenzocyclooctyne-modified thrombin-specific HD22 aptamer is clicked on the PEDOT-N₃-OECTs, showing the application of the devices toward the development of organic transistors-based biosensors. Finally, the clicked OECTs preserve their electronic features after the different clicking procedures, demonstrating the stability and robustness of the fabricated transistors.

Electrochemical Quantification of Glycated and Non-glycated Human Serum Albumin in Synthetic Urine

A polymer-based electrode capable of specific detection of human serum albumin, and its glycated derivatives, is described. The sensor is constructed from a glass microscope slide coated with a synthesized, polythiophene film bearing a protected, iminodiacetic acid motif. The electrode surface is then further elaborated to a functional biosensor through deprotection of the iminodiacetic acid, followed by metal-affinity immobilization of a specific and high-affinity, albumin ligand. Albumin was then quantified in buffer and synthetic urine via electrochemical impedance spectroscopy. Glycated albumin was next bound to a boronic acid-modified, single-cysteine dihydrofolate reductase variant to quantify glycation ratios by square-wave voltammetry. The platform offers high sensitivity, specificity, and reproducibility in an inexpensive arrangement. The detection limits exceed the requirements for intermediate-term glycemic control monitoring in diabetes patients at 5 and 1 nM for albumin and its glycated forms, respectively.

Freestanding flexible polymer films based on bridging of two EDOT units with functionalized chains for use in long-term-stable supercapacitors

Freestanding flexible films were prepared by cross-linking two EDOT unit with fictionalized flexible chains, the application of these films in supercapacitors showed excellent cycling life.

Poly(3,4-ethylenedioxythiophene) (PEDOT) Derivatives: Innovative Conductive Polymers for Bioelectronics

Poly(3,4-ethylenedioxythiophene)s are the conducting polymers (CP) with the biggest prospects in the field of bioelectronics due to their combination of characteristics (conductivity, stability, transparency and biocompatibility). The gold standard material is the commercially available poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). However, in order to well connect the two fields of biology and electronics, PEDOT:PSS presents some limitations associated with its low (bio)functionality. In this review, we provide an insight into the synthesis and applications of innovative poly(ethylenedioxythiophene)-type materials for bioelectronics. First, we present a detailed analysis of the different synthetic routes to (bio)functional dioxythiophene monomer/polymer derivatives. Second, we focus on the preparation of PEDOT dispersions using different biopolymers and biomolecules as dopants and stabilizers. To finish, we review the applications of innovative PEDOT-type materials such as biocompatible conducting polymer layers, conducting hydrogels, biosensors, selective detachment of cells, scaffolds for tissue engineering, electrodes for electrophysiology, implantable electrodes, stimulation of neuronal cells or pan-bio electronics.

A novel self-healing electrochromic film based on a triphenylamine cross-linked polymer

A novel electrochromic material with self-healing properties, which may hold great potential to overcome the scar generation in ECDs, has been synthesized and studied.

A Thiophene-Containing Conductive Metallopolymer Using an Fe(II) Bis(terpyridine) Core for Electrochromic Materials

Three Fe(II) bis(terpyridine)-based complexes with thiophene (Fe(L1)₂), bithiophene (Fe(L2)₂), and 3,4-ethylenedioxythiophene (Fe(L3)₂) side chains were designed and synthesized for the purpose of providing two terminal active sites for electrochemical polymerization. The corresponding metallopolymers (poly-Fe(Ln)₂, n = 2 or 3) were synthesized on indium tin oxide (ITO)-coated glass substrates via oxidative electropolymerization of the thiophene-substituted monomers and characterized using electrochemistry, X-ray photoelectron spectroscopy, UV-vis spectroscopy, and atomic force microscopy. The film poly-Fe(L2)₂ was further studied for electrochromic (EC) color-switching properties and fabricated into a solid-state EC device. Poly-Fe(L2)₂ films exhibit an intense MLCT absorption band at 596 nm (ε = 4.7 × 10⁴ M^-1 cm^-1) in the UV-vis spectra without any applied voltage. Upon application of low potentials (between 1.1 and 0.4 V vs Fc⁺/Fc), the obtained electropolymerized film exhibited great contrast with a change of transmittance percentage (ΔT%) of 40% and a high coloration efficiency of 3823 cm² C^-1 with a switching time of 1 s. The film demonstrates commonplace stability and reversibility with a 10% loss in peak current intensity after 200 cyclic voltammetry cycles and almost no loss in change of transmittance (ΔT%) after 900 potential switches between 1.1 and 0.4 V (vs Fc⁺/Fc) with a time interval of 0.75 s. The electropolymerization of Fe(L2)₂ provides convenient and controllable film fabrication. Electrochromic behavior was also achieved in a solid-state device composed of a poly-Fe(L2)₂ film and a polymer-supported electrolyte sandwiched between two ITO-coated glass electrodes.

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

A new versatile polythiophene building block, 3-(3,4-ethylenedioxythiophene)prop-1-yne (pyEDOT) (3), is prepared from glycidol in four steps in 28% overall yield. pyEDOT features an ethynyl group on its ethylenedioxy bridge, allowing further functionalization by alkyne chemistry. Its usefulness is demonstrated by a series of functionalized polythiophene derivatives that were obtained by pre- and post-electropolymerization transformations, provided by the synthetic ease of the Sonogashira coupling and click chemistry.

Multichromophoric electrochromic polymers: colour tuning of conjugated polymers through the side chain functionalization approach

Organic electrochromic materials have gained constantly increasing interest over the years with respect to their inorganic counterpart due to essentially two distinctive characteristics: their processability through solution based low cost processes and their wide colour palette. Such characteristic features enabled their application in displays, smart windows, electronic paper and ophthalmic lenses. Alongside the established concept of donor-acceptor polymers, side chain functionalized multichromophoric polymers are gaining attention as a highly performing and synthetically feasible alternative, particularly relevant to applications requiring a complete colourlessness in one of the accessible redox states of the material. The primary aim of the present article is to review all the results involving the tuning of the native electrochromic properties of simple conjugated polymers through the introduction of a discrete electrochromic molecule as a side chain substituent.

Functionalized branched EDOT-terthiophene copolymer films by electropolymerization and post-polymerization "click"-reactions

The electrocopolymerization of 3,4-ethylenedioxythiophene (EDOT) with the branched thiophene building block 2,2':3',2″-terthiophene (3T) is presented as a versatile route to functional polymer films. Comparisons to blend systems of the respective homopolymers PEDOT and P3T by in situ spectroelectrochemistry and Raman spectroscopy prove the successful copolymer formation and the access to tailored redox properties and energy levels. The use of EDOT-N3 as co-monomer furthermore allows modifications of the films by polymer analogous reactions. Here, we exemplarily describe the post-functionalization with ionic moieties by 1,3-dipolar cycloaddition ("click"-chemistry) which allows to tune the surface polarity of the copolymer films from water contact angles of 140° down to 40°.

Synthesis of novel chiral l-leucine grafted PEDOT derivatives with excellent electrochromic performances

PEDOT–Boc–Leu and PEDOT–Leu exhibit excellent electrochromic performance, and are promising optoelectronic materials.

Reversible electroswitchable luminescence in thin films of organic-inorganic hybrid assemblies

In this study, reversible electroswitched luminescence is realized in a novel hybrid composite of organic-inorganic polymers and Pyronin Y-doped silica nanoparticles (PYDS) in aqueous solutions for the first time. The electrochromic material, poly (3,4-ethylenedioxythiophene) (PEDOT), is electrodeposited on the electrode in the presence of phosphododecamolybdic acid (PMo(12)). The luminescence of PYDS can be effectively switched between "on" and "off" states by applying oxidation and reduction potentials of PEDOT via the corresponding luminescence quenching effect. The electrochromic devices (ECDs) we report here exhibit lots of advantages, such as easy fabrication, high contrast of fluorescence response, good reversibility, and long-time stability. The creative application of PEDOT in ECDs in aqueous solutions is anticipated to offer important hints and a basis for other organic materials in the field of photoelectric devices.

2-Chloro-methyl-2,3-dihydro-thieno[3,4-b][1,4]dioxine

In the mol-ecule of the title compound, C(7)H(7)ClO(2)S, the six-membered ring adopts a twisted conformation. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules. There is also a weak C-H⋯π inter-action.