PEDOT Nanoparticles Research Articles

Electroactive self-standing polyester membranes prepared using magnetite/poly(3,4-ethylenedioxythiophene) core-shell particles

In this work hybrid magnetite (Fe3O4)/poly(3,4-ethylenedioxythiophene) (PEDOT) core-shell particles are used to produce electro-responsive self-standing polycaprolactone (PCL) membranes with many potential applications. For this purpose, Fe3O4/PEDOT core-shell particles with different magnetite contents are prepared by combining chemical precipitation and emulsion polymerization. After chemical, morphological and physical characterization, the electrochemical response of the hybrid particles is analyzed and compared with that of PEDOT nanoparticles. In all cases, Fe3O4/PEDOT core-shell particles are more electroactive than PEDOT particles, with the electrochemical response of the former increasing with the content of magnetite. Composite membranes were prepared by spin-coating a mixture of polycaprolactone (PCL) and Fe3O4/PEDOT particles. The resulting Fe3O4/PEDOT-PCL membranes, which maintained the magnetic behavior, were transformed into electro-responsive by incorporating a PEDOT surface layer through anodic polymerization, which was possible thanks to the role of Fe3O4/PEDOT particles as polymerization nuclei. One of the potential applications of self-supported electro-responsive Fe3O4/PEDOT-PCL/PEDOT membranes was illustrated through a proof-of-concept. Specifically, a wide-spectrum antibiotic, chloramphenicol, was loaded into the membranes during the anodic polymerization step promoted by the hybrid Fe3O4/PEDOT particles and, subsequently, completely released by electrical stimulation. Overall, Fe3O4/PEDOT core-shell particles allowed us to obtain self-standing membranes with electric and magnetic properties, as promising candidates for many technological applications.

Structural optimization of ion storage layer for highly stable electrochromic devices based on polythiophene derivative films

Due to their rich color, fast switching speed and high coloration efficiency, polymer-based electrochromic devices (ECDs) have broad application prospects in various fields such as smart windows, anti-glare rearview mirrors, displays and adaptive camouflage. However, the preparation of highly stable polymer-based ECDs is still a great challenge. Herein, we present a simple and efficient strategy to construct the poly (3,4-ethylenedioxythiophene) (PEDOT)-multi-walled carbon nanotubes (MWCNTs) composite film or PEDOT/MWCNTs bilayer film, which serves as ion storage layer. The ECDs are assembled with poly (3-hexylthiophene) (P3HT) as EC layer due to its good EC behavior. The P3HT film was prepared by potentiostatic deposition, and the PEDOT, PEDOT-MWCNTs and PEDOT/MWCNTs films were obtained by spray-coating technology. We investigated the structure, morphology and electrochemical performance of P3HT, PEDOT, PEDOT-MWCNTs and PEDOT/MWCNTs films, and EC properties of devices. The results indicate that the rough and porous P3HT film consists of many nanoparticles. Compared with PEDOT-MWCNTs composite film, the PEDOT/MWCNTs film is more loose and porous, where PEDOT nanoparticles and some PEDOT nanosheets are coated on a three-dimensional skeleton film of MWCNTs. These films possess good electrochemical performance. The ECD based on P3HT and PEDOT/MWCNTs films achieves an optical contrast of 38 % and coloration efficiency of 375 cm2/C, exhibiting good cyclic stability (retaining 92 % of initial optical contrast after 2000 cycles). Its coloration time and bleaching time are 0.60 and 1.83 s, respectively. This study suggests that structural optimization of ion storage layer might be a facile strategy for fabricating highly stable polymer-based ECDs.

Facile synthesis of PEDOT@rGO nanocomposites for novel electrochemical sensor for the determination of 4-chlorophenol in a real water sample

A sensitive electrochemical sensor was developed for the detection of 4-chlorophenol (4-CP) using the nanocomposite based on poly (3,4-ethylenedioxythiophene) and reduced graphene oxide (PEDOT-rGO). The GC electrode modified with the proposed nanocomposite was characterized using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and electrochemical impedance spectroscopy. The Raman analysis confirmed the successful incorporation of PEDOT onto the reduced graphene oxide (rGO) surface. It is also observed in the SEM analysis that PEDOT nanoparticles were spread over the rGO sheet. The lower charge transfer resistance (Rct) values for PEDOT-rGO/GCE compared to PEDOT/GCE in electrochemical impedance spectroscopy confirms the unique conducting properties of rGO and the higher surface area of PEDOT in the proposed composite on the GCE surface. The cyclic voltammetric and differential pulse voltammetric (DPV) results has indicated that the PEDOT-rGO-modified glassy carbon electrode is an excellent electrocatalyst for the detection of 4-CP compared to PEDOT and rGO. This counterpart exhibited a good linear relationship in the range of 5–250 μM, with a detection limit of 12 nM in the DPV technique. This sensor was also employed for the determination of 4-CP in river water samples. The accuracy of the analytical electrochemical sensor for 4-CP was comparatively analyzed using the obtained UV–visible spectral data, indicating a detection limit of 21 nM. Hence, the electrochemical method was successfully employed to obtain a lower detection limit for 4-CP than that for electronic absorption spectral observations. All the observed results were consistent with our expectations and showed that this novel PEDOT-rGO/GCE has good repeatability and stability and without any impactable interference behavior.

A 3D printable gelatin methacryloyl/chitosan hydrogel assembled with conductive PEDOT for neural tissue engineering

In neural tissue engineering, biomaterial scaffolds that have high conductivity and customized structures are crucial in promoting nerve regeneration. Poly(3,4-ethylenedioxythiophene) (PEDOT) has emerged as a promising conductive polymer with excellent chemical stability and biocompatibility. However, traditional three-dimensional (3D) printing of PEDOT-based conductive scaffolds faces challenges in limited printing resolution, poor solubility, and brittleness of conductive materials. Herein, digital light processing (DLP) printing was used to fabricate complex hydrogel structures using gelatin methacryloyl (GelMA) and chitosan (CS) while incorporating PEDOT nanoparticles through interfacial polymerization to create conducting pathways within a hydrogel structure. The integration of PEDOT significantly enhanced the electrical conductivity and mechanical properties of the GelMA/CS hydrogel while preserving printed details. The GelMA/CS-PEDOT hydrogel promoted cell proliferation and facilitated axon outgrowth of PC12 cells and Schwann cells during in vitro culture. Moreover, in vitro direct current electrical stimulation promoted axon elongation of PC12 cells cultured on a conductive substrate. In vivo studies used a conductive nerve conduit to repair a 10-mm rat sciatic nerve defect, validating the efficacy of GelMA/CS-PEDOT scaffold in peripheral nerve injury repair. These findings highlight the significant potential of conductive GelMA/CS-PEDOT hydrogel in the field of neural tissue engineering.

Synthesis strategies and cancer therapy applications of PEDOT nanoparticles

PEDOT nanoparticles combine controlled drug release, and photothermal ablation due to their electrical and thermal properties. This review delves into their synthesis methods, characterization and potential in targeted cancer therapies.

Bio-mimetic selectivity in Hg2+ sensing developed via electro-copolymerized PEDOT and benzothiazole-Au nanoparticles composite.

To eliminate the potential health risksof mercury, development of stable and selective mercury sensor with high sensitivity is the need of the hour. To address this, a novel PEDOT-AA-BTZ-Au-based Hg2+ selective, hybrid electrochemical sensor has been designed by following a simple protocol for electrode fabrication. The electrode was designed by carefully optimizing the onset oxidation potential of supramolecule 2-(anthracen-9-yl)benzo[d]thiazole (AA-BTZ) and conducting polymer poly-(3,4-ethylenedioxythiophene) (PEDOT), using copolymerization approach followed by dropcasting of gold nanoparticles (AuNPs). The designed electrode offered synergistic effects thus augmenting the electrical conductivity and adsorption capacity as depicted by its porous surface morphology. The highly sensitive analytical signal was generated by sulphur pockets present in AA-BTZ and PEDOT conducting framework. This is further complemented by the selectivity offered by the soft interactions between AuNPs and Hg2+ resulting in a low detection limit of 0.60 nM. The prepared system was further utilized for sensing Hg2+ ion in real systems including lake water and cosmetic samples. Lowinterference from other ions and better reproducibility further established the suitability of the designed transducer system for future on-site sensing.

Energy filtering effect of flexible organic/inorganic nanocomposite thermoelectric fabrics to harvest human heat and solar energy

PEDOT has caught much attention because of its intrinsic electrical conductivity and flexibility. However, PEDOT has a low Seebeck coefficient that prevents its practical applications in the smart wearable field and this problem is one challenge faced by scientists today. Hence, in this study, polypropylene nonwovens (PP) that received hydrophilic treatment in advance were used as matrices (PP-PDA). The matrices underwent the low temperature interfacial polymerization technology and coating treating, and were 4 thus deposited with PEDOT and high thermoelectric performance inorganic nanoparticles (CuI), thereby forming high performance thermoelectric fabric (PP-PDA-PEDOT/CuI) having a core-shell structure. PEDOT and nanoparticles (CuI) have energy filtering effect that improves the Seebeck coefficient thermoelectric fabrics, Seebeck coefficient from 13.53 μV/K elevated to 83.02 μV/K. Next, thermoelectric fabrics were assembled into thermoelectric devices with five pairs that can collect both the body heat and the solar energy. When users put on the thermoelectric devices, a temperature difference of 10 °C generates voltage of 2.264 mV. Specifically, with a temperature difference being 30 °C, thermoelectric devices were able to generate output voltage of 5.5 mV. which proves that the wearable thermoelectric devices become an effective strategy for the applications of the smart textiles field.

Electroconductive poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticle-loaded silk fibroin biocomposite conduits for peripheral nerve regeneration

Peripheral nerve injury (PNI) often clinically relies on the use of nerve grafts taken from the patient to establish a therapeutic effect, though secondary site of injury and morbidity have prompted the medical community to find alternative solutions. A new trend in the development of biomaterials arises in the form of electro-conductive biomaterials, especially for electrically active tissues such as the peripheral nerves. In this work, novel poly(3,4-ethylenedioxythiophene) PEDOT nanoparticles (PEDOT NPs) were synthetized via the mini-emulsion method and were combined with silk fibroin (SF) to create conduits for PNI repair. The synthesized PEDOT NPs-loaded SF conduits showed optimal properties for peripheral nerve substitution from the physico-chemical and biological point of view. They displayed excellent mechanical and conductivity performance with the tensile moduli reaching 6.61 ± 0.55 MPa and the conduits reaching 5.4 · 10–4 S cm−1, respectively. The conduits did not possess apatite-forming capacity, which were resistant to bending occlusions for angles up to 50° and to suturing. The developed conduits are promising as a novel biomaterial for applications in peripheral nerve regeneration; in vitro experiments showed that they did not allow BJ fibroblast infiltration, avoiding scar tissue formation in the lumen, and they did not show any toxic effect for Schwann cells.

One-pot strategy to fabricate conductive cellulose nanocrystal-polyethylenedioxythiophene nanocomposite: Synthesis mechanism, modulated morphologies and sensor assembly

Simple preparation, good conductivity, and excellent hydrophilicity are in urgent demand due to fast growth of wearable intelligent devices. Cellulose nanocrystal-polyethylenedioxythiophene (CNC-PEDOT) nanocomposites with modulated morphology were prepared through Iron (III) p-toluenesulfonate hydrolysis of commercialized microcrystalline cellulose (MCC) and in situ polymerization of 3,4-ethylenedioxythiophene monomers (EDOT) through one-pot green synthesis, where preparation and modification of CNC were obtained for uses as templates to anchor PEDOT nanoparticles. The resultant CNC-PEDOT nanocomposite gave well-dispersed PEDOT nanoparticles with sheet-like structure on the CNC surface, possessing higher conductivity and improved hydrophilicity or dispersibility. Subsequently, a wearable non-woven fabrics (NWF) sensor was successfully assembled by dipping the conductive CNC-PEDOT, and showed excellent sensing response for multiple signals (subtle deformation from various human activities and temperature). This study provides a feasible and large-scale production of CNC-PEDOT nanocomposites and their applications in wearable flexible sensors and electronic devices.

Nanostructured PEDOT-based multilayer thin films with high thermoelectric performances

Intrinsically conductive polymers are considered as one of the most promising candidates for thermoelectric (TE) materials due to their outstanding properties. Prior studies have been primarily focused on conducting polymers such as polyaniline, polypyrrole, polythiophene, and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). In particular, currently available cationic water-soluble conjugated polymers are limited because of difficulties in synthetic routes. Herein, a positively charged PEDOT nanoparticles (PEDOT:NPs) dispersed in water are synthesized to serve as a structure directing agent for the development of hierarchical architectures with high flexibility and TE performances. A completely organic composite is fabricated by alternately depositing layers of aqueous solutions of PEDOT:NPs and double-walled carbon nanotubes (DWNT) stabilized with PEDOT:PSS via a layer-by-layer methodology. A 20 bilayer thin film (≈ 2.1 µm thick), comprised of a PEDOT:NPs/DWNT-PEDOT:PSS repeating sequence, exhibits high electrical conductivities of up to 744 S cm−1 and a high Seebeck coefficient up to 83 µV K−1. As a result, the multilayer thin films achieve a power factor of 512 µW m−1 K−2. These excellent TE properties can be attributed to the formation of a three-dimensional conjugated network with a highly ordered structure, which facilitates carrier transport within the film. This organic composite, based on a newly synthesized conducting polymer, with high flexibility and power factor offers a promising route to utilize efficient thermoelectric devices on flexible surfaces.

Simple modification to allow high-efficiency and high-resolution multi-material 3D-printing fabrication of microfluidic devices.

Advances in the instrumentation and materials for photopolymerization 3D printing aided the use of this powerful technique in the fabrication of microfluidic devices. The costs of printers and supplies have been reduced to the point where this technique becomes attractive for prototyping microfluidic systems with good resolution. With all the development of multi-material 3D printers, most of the microfluidic devices prepared by photopolymerization 3D printing are based on a single substrate material. We developed a digital light processing multi-material 3D printer where two or more resins can be used to prepare complex objects and functional microfluidic devices. The printer is based on a vat inclination system and embedded peristaltic pumps that allow the injection and removal of resins and cleaning step between material changes. Although we have built the whole system, the modification can be incorporated into commercially available printers. Using a high-resolution projector, microfluidic channels as narrow as 43 μm were obtained. We demonstrate the printing of multi-material objects containing flexible, rigid, water-soluble, fluorescent, phosphorescent, and conductive (containing PEDOT or copper nanoparticles) resins. An example of a microfluidic chip containing electrodes for electrochemical detection is also presented.

Carboxymethyl Chitosan and Gelatin Hydrogel Scaffolds Incorporated with Conductive PEDOT Nanoparticles for Improved Neural Stem Cell Proliferation and Neuronal Differentiation

Tissue engineering scaffolds provide biological and physiochemical cures to guide tissue recovery, and electrical signals through the electroactive materials possess tremendous potential to modulate the cell fate. In this study, a novel electroactive hydrogel scaffold was fabricated by assembling poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles on a carboxymethyl chitosan/gelatin (CMCS/Gel) composite hydrogel surface via in situ chemical polymerization. The chemical structure, morphology, conductivity, porosity, swelling rate, in vitro biodegradation, and mechanical properties of the prepared hydrogel samples were characterized. The adhesion, proliferation, and differentiation of neural stem cells (NSCs) on conductive hydrogels were investigated. The CMCS/Gel-PEDOT hydrogels exhibited high porosity, excellent water absorption, improved thermal stability, and adequate biodegradability. Importantly, the mechanical properties of the prepared hydrogels were similar to those of brain tissue, with electrical conductivity up to (1.52 ± 0.15) × 10-3 S/cm. Compared to the CMCS/Gel hydrogel, the incorporation of PEDOT nanoparticles significantly improved the adhesion of NSCs, and supported long-term cell growth and proliferation in a three-dimensional (3D) microenvironment. In addition, under the differentiation condition, the conductive hydrogel also significantly enhanced neuronal differentiation with the up-regulation of β-tubulin III expression. These results suggest that CMCS/Gel-PEDOT hydrogels may be an attractive conductive substrate for further studies on neural tissue repair and regeneration.

Antifouling zwitterionic peptide hydrogel based electrochemical biosensor for reliable detection of prostate specific antigen in human serum

An electrochemical biosensor based on the antifouling zwitterionic peptide hydrogel (CFEFKFC) and the poly(3,4-ethylenedioxythiophene) (PEDOT) was fabricated to accurately detect prostate specific antigen (PSA) in complex human serum. The electrode was modified with the conducting polymer PEDOT and gold nanoparticles (AuNPs) in sequence through electrodeposition, and then the designed zwitterionic peptide hydrogel prepared through self-assembly was immobilized onto the modified electrode surface via the Au–S bond. The zwitterionic peptide hydrogel with cysteine terminal is easy for immobilization onto the gold surface, and it is also suitable for the immobilization of biomolecules such as PSA antibody in this work, through the formation of covalent amide bonds. The peptide hydrogel possessed excellent antifouling property, and it was able to effectively prevent the adsorption of nonspecific proteins, cells and other biomolecules. The developed antifouling biosensor showed a linear response range from 0.1 ng mL−1 to 100 ng mL−1, with a low limit of detection down to 5.6 pg mL−1. These results encourage the wide use of zwitterionic peptide hydrogels as antifouling materials in various sensing and bio-sensing devices.

Combining rapid and sustained insulin release from conducting hydrogels for glycemic control

Innovative insulin delivery systems contemplate combining multi-pharmacokinetic profiles for glycemic control. Two device configurations have been designed for the controlled release of insulin using the same chemical compounds. The first insulin delivery system, which displays a rapid release response that, in addition, is enhanced on a short time scale by electrical stimulation, consists on an insulin layer sandwiched between a conducting poly(3,4-ethylenedioxythiophene) (PEDOT) film and a poly-γ-glutamic acid (γ-PGA) hydrogel. The second system is constituted by γ-PGA hydrogel loaded with insulin and PEDOT nanoparticles by in situ gelation. In this case, the insulin release, which only starts after the degradation of the hydrogel over time (i.e. on a long time scale), is slow and sustained. The combination of an on-demand and fast release profile with a sustained and slow profile, which act on different time scales, would result in a very efficient regulation of diabetes therapy in comparison to current systems, allowing to control both fast and sustained glycemic events. Considering that the two systems developed in this work are based on the same chemical components, future work will be focused on the combination of the two kinetic profiles by re-engineering a unique insulin release device using γ-PGA, PEDOT and insulin.

Electroconductive PEDOT nanoparticle integrated scaffolds for spinal cord tissue repair

BackgroundHostile environment around the lesion site following spinal cord injury (SCI) prevents the re-establishment of neuronal tracks, thus significantly limiting the regenerative capability. Electroconductive scaffolds are emerging as a promising option for SCI repair, though currently available conductive polymers such as polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) present poor biofunctionality and biocompatibility, thus limiting their effective use in SCI tissue engineering (TE) treatment strategies.MethodsPEDOT NPs were synthesized via chemical oxidation polymerization in miniemulsion. The conductive PEDOT NPs were incorporated with gelatin and hyaluronic acid (HA) to create gel:HA:PEDOT-NPs scaffolds. Morphological analysis of both PEDOT NPs and scaffolds was conducted via SEM. Further characterisation included dielectric constant and permittivity variances mapped against morphological changes after crosslinking, Young’s modulus, FTIR, DLS, swelling studies, rheology, in-vitro, and in-vivo biocompatibility studies were also conducted.ResultsIncorporation of PEDOT NPs increased the conductivity of scaffolds to 8.3 × 10–4 ± 8.1 × 10–5 S/cm. The compressive modulus of the scaffold was tailored to match the native spinal cord at 1.2 ± 0.2 MPa, along with controlled porosity. Rheological studies of the hydrogel showed excellent 3D shear-thinning printing capabilities and shape fidelity post-printing. In-vitro studies showed the scaffolds are cytocompatible and an in-vivo assessment in a rat SCI lesion model shows glial fibrillary acidic protein (GFAP) upregulation not directly in contact with the lesion/implantation site, with diminished astrocyte reactivity. Decreased levels of macrophage and microglia reactivity at the implant site is also observed. This positively influences the re-establishment of signals and initiation of healing mechanisms. Observation of axon migration towards the scaffold can be attributed to immunomodulatory properties of HA in the scaffold caused by a controlled inflammatory response. HA limits astrocyte activation through its CD44 receptors and therefore limits scar formation. This allows for a superior axonal migration and growth towards the targeted implantation site through the provision of a stimulating microenvironment for regeneration.ConclusionsBased on these results, the incorporation of PEDOT NPs into Gel:HA biomaterial scaffolds enhances not only the conductive capabilities of the material, but also the provision of a healing environment around lesions in SCI. Hence, gel:HA:PEDOT-NPs scaffolds are a promising TE option for stimulating regeneration for SCI.

Facile synthesis of highly conductive and dispersible PEDOT particles

Poly(3,4-ethylene dioxythiophene) (PEDOT) is widely used in electronics for its excellent conducting property. However, it is challenging to synthesize PEDOT nanoparticles with high conductivity and high dispersibility in various organic solvents. We introduce a novel strategy for synthesizing highly conductive, dispersible PEDOT particles in a binary organic solvent system. The synthesis strategy is based on a standard chemical oxidation procedure, which uses ferric chloride (FeCl 3 ) as the oxidant without any post-doping process in a mixed solvent of dichloromethane and acetonitrile (CH 2 Cl 2 and CH 3 CN). By optimizing the synthesis process, high-quality colloidal PEDOT nanoparticles (average diameter is around 50 nm) are obtained with a high yield of over 75%. These nanoparticles show a maximum electrical conductivity of 220 S/cm, which is close to the highest electrical conductivity of the current solid PEDOT powder. Moreover, these particles can be dispersed in various organic solvents and water without a surfactant and maintain stable conductivity for over one month. This outstanding processability and conductivity could reinforce thermoplastic polyurethane resins as conductive composites. Prototyped applications of the PEDOT nanoparticles as supercapacitor materials are demonstrated. The PEDOT nanoparticles show a high specific capacitance of 280 F/g, comparable to other reported PEDOT materials prepared using various templates. • Colloidal PEDOT nanoparticles with a conductivity of 220 S/cm are obtained. • These particles are dispersible in various organic solvents or water. • These particles are potentially for supercapacitor and conductive additives.

Synthesis of conductive polymeric nanoparticles with hyaluronic acid based bioactive stabilizers for biomedical applications

In recent years, the use of organic materials to infer conductivity in biomedical devices has received increasing attention. Typical inorganic semiconductors and conductors are rigid and expensive, usually require multiple processing steps and are unsuitable for biomedical applications. Electrochemically or chemically doped conjugated polymers help to overcome these problems due to their stability, low cost, light weight and excellent electrical and optical properties. The conducting polymer poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is the material of choice for biomedical applications as it is water soluble, however, there are growing concerns around its stabilizer, PSS, due to its release of acidic products upon degradation in-vivo. Here, we report the successful synthesis of PEDOT nanoparticles using hyaluronic acid (HA) as a stabilizer via an oxidative miniemulsion polymerisation technique. This improves the bioactivity and hydrophilicity of nanoparticles. The effect of varying amounts of HA and different molar ratios of EDOT:TOS has been studied and their role in the conductive and morphological properties of final nanoparticles has been fully elucidated. Furthermore, bioactivity and biocompatibility of the nanoparticles are demonstrated for customizable in vivo applications. Nanoparticles were found to have a conductivity up to 10 times greater than pristine PEDOT:PSS with increased addition of oxidant. The proposed easy-to-manufacture approach, along with the highlighted superior properties, expands the potential of conductive polymers in future customizable biological applications such as tissue scaffolds, nerve conduits and cardiac patches and represents a real breakthrough from the current state of the art.

Polypeptide hydrogel loaded with conducting polymer nanoparticles as electroresponsive delivery system of small hydrophobic drugs

A hydrogel/nanoparticle-loaded system for the controlled delivery of small hydrophobic drugs has been prepared using poly(γ-glutamic acid) (PGGA), a naturally occurring biopolymer made of glutamic acid units connected by amide linkages between α-amino and γ-carboxylic acid groups, and poly(3,4-ethylenedioxythiophene) (PEDOT), a very stable conducting polymer with excellent electrochemical response. Specifically, curcumin (CUR)-loaded PEDOT nanoparticles (PEDOT/CUR) were incorporated to the PGGA hydrogel during the crosslinking reaction. After chemical, morphological and electrochemical characterization, the release profiles of PEDOT/CUR and PGGA/PEDOT/CUR system have been compared in absence and presence of electrical stimuli, which consisted on the application of a voltage of –0.5 V for 15 min every 24 h. Results show that the release is higher for electrically stimulated systems by more than twice, even though due to its hydrophobicity and poor solubility in water the release was relatively slow in both cases. This feature could be advantageous when the therapeutic treatment requires slow, controlled and sustained CUR release.

Morphology-Dependent Delamination Performance of Poly (3,4-ethylenedioxythiophene) for Corrosion Protection on Iron

Two different types of poly (3,4-ethylenedioxythiophene) (PEDOT) composite morphologies in organic coatings were prepared by using either PEDOT nanoparticles or PEDOT/carbon nanotubes (PEDOT/CNTs). The PEDOT additives were prepared by emulsion polymerization. The morphology of the resultant samples was characterized by scanning electron microscopy. The composite coatings were prepared by incorporating PEDOT into a polyvinyl butyral (PVB) matrix and applied on an iron substrate. The delamination behavior of the as-prepared samples for corrosion protection was characterized by the scanning Kelvin probe (SKP) technique. The SKP measurements showed that the composite coatings with PEDOT nanoparticles exhibited the best delamination resistance. This could be possibly due to the fact that, for a polarization of the interface, the solid particles have a higher overall stored charge and a good electronic connection at the interface. The performance of the composite coating with 10 vol% of PEDOT nanoparticles was significantly better than for the coatings with 5 vol% and 20 vol%.

PEDOT-AuNPs-based impedimetric immunosensor for the detection of SARS-CoV-2 antibodies

Electrochemical sensors and biosensors are useful techniques for fast, inexpensive, sensitive, and easy detection of innumerous specimen. In face of COVID-19 pandemic, it became evident the necessity of a rapid and accurate diagnostic test, so the impedimetric immunosensor approach can be a good alternative to replace the conventional tests due to the specific antibody-antigen binding interaction and the fast response in comparison to traditional methods. In this work, a modified electrode with electrosynthesized PEDOT and gold nanoparticles followed by the immobilization of truncated nucleoprotein (N aa160–406aa) was used for a fast and reliable detection of antibodies against COVID-19 in human serum sample. The method consists in analyzing the charge-transfer resistance (RCT) variation before and after the modified electrode comes into contact with the positive and negative serum sample for COVID-19, using [Fe(CN)6]3-/4− as a probe. The results show a linear and selective response for serum samples diluted in a range of 2.5 × 103 to 20 × 103. Also, the electrode material was fully characterized by Raman spectroscopy, transmission electron microscopy and scanning electron microscopy coupled with EDS, indicating that the gold nanoparticles were well distributed around the polymer matrix and the presence of the biological sample was confirmed by EDS analysis. EIS measurements allowed to differentiate the negative and positive samples by the difference in the RCT magnitude, proving that the material developed here has potential properties to be applied in impedimetric immunosensors for the detection of SARS-CoV-2 antibodies in about 30 min.