A dual‐functional device is fabricated to release progressively dopamine (DA) from a biohydrogel under real‐time monitoring via electrochemical detection. For this purpose, a poly‐γ‐glutamic acid biohydrogel is assembled with a poly(3,4‐ethylenedioxythiophene) (PEDOT) layer, previously deposited onto a screen printed electrode. The biohydrogel is formulated to achieve dimensional stability and maximum DA‐loading capacity. Conditions for DA‐loading are influenced by the oxidation of the neurotransmitter in acid environments and the poor resistance of PEDOT to the lyophilization. The performance of the device is proved in a medium with the physiological pH of blood and the cerebrospinal fluid. The progressive release of DA is successfully monitored by the device, the limit of detection and sensitivity of the integrated sensor being 450 × 10−9m and 8 × 10−5 mA µm−1, respectively. The effect of electrochemical stimulation in the kinetics of the DA release is also investigated applying potential ramps in cyclic phase to alter the biohydrogel morphology. 相似文献
A simple and sensitive method is described for the electrochemical determination of shikonin, a widely used anti‐tumoral agent, based on its electrochemical oxidation at a nanostructured poly(hydroxymethylated‐3,4‐ethylenedioxy‐thiophene) (PEDOT‐MeOH) electrode, which was fabricated by a facile electropolymerization method. Compared with bare and poly(3,4‐ethylenedioxythiophene) (PEDOT) electrodes, the PEDOT‐MeOH film exhibited a distinctly higher activity for the electrooxidation of shikonin. The PEDOT‐MeOH electrode showed a wide linear response for shikonin in the concentration range from 1.0 nM to 10.0 µM with detection limit of 0.3 nM. Furthermore, the PEDOT‐MeOH electrode displayed high stability, good reproducibility and high sensitivity for the detection of shikonin. 相似文献
A glassy carbon electrode (GCE) was covalently modified by 4‐phosphatephenyl (4‐PP). Sensing paracetamol (PCT) via linear sweep voltammetry in sulfuric buffer solution of pH 1.02 at 36.8 °C, the 4‐PP‐modified GCE showed high electrochemical sensitivity and long reusability. PCT‐loaded poly(vinyl alcohol) (PVA) nanofibers were prepared by electrospinning. Based on the calibration curve of PCT on the 4‐PP‐modified GCE, the PCT release process from the nanofibers was electrochemically monitored in real time via two routes. The results showed that the covalently modified GCE can be repeatedly used as real‐time electrochemical monitoring platform for drug release from drug‐loaded nanofibers in the long term. 相似文献
By exploiting the electrostatic interaction between positively charged 3,4‐ethylenedioxythiophene cation radicals and negatively charged sulfonated graphene (SG) sheets, we prepared a poly(3,4‐ethylenedioxythiophene)‐sulfonated graphene (SG‐PEDOT) composite film by a one‐step electrochemical process. The composite was further decorated with gold nanoparticles (AuNPs) and employed as an electrode material for the detection of L ‐cysteine (Cys). The SG‐PEDOT composite film is shown to provide a rough surface for the electrodeposition of AuNPs and to improve substrate accessibility and interaction with Cys. Moreover, the AuNPs‐decorated composite exhibits better electrocatalytic performance than that of a SG‐PEDOT composite only. Under optimum experimental conditions, the amperometric current of the sensor is linearly related to the concentration of Cys in the 0.1 to 382 µM range, and the detection limit is 0.02 µM (at S/N=3). The modified electrode displays favorable selectivity, good stability and high reproducibility. The method was successfully applied to the detection of Cys in spiked human urine. 相似文献
In this work, we developed a roll‐to‐roll printed poly(3,4‐ethylenedioxythiophene)/polystyrene sulphoanate without graphene oxide (GO) (PEDOT/PSS) and with graphene oxide (PEDOT/PSS/GO) plastic films for the electrochemical determination of carbofuran. Both the PEDOT/PSS and PEDOT/PSS/GO plastic films showed electroactivity towards the oxidation of carbofuran. Incorporation of graphene oxide (GO) improves the electrochemical activity of carbofuran and increased its sensitivity. The printed plastic films were characterized by cyclic voltammetry (CV), linear sweep voltammetry (LSV), surface profilometer, four point probe and atomic force microscopy (AFM). The effects of pH, deposition time, deposition potential and film thickness on the oxidation peak current of carbofuran were investigated. Under the optimized conditions, a dynamic linear range of 1 μM–90 μM with a detection limit of 1.0×10?7 M (S/N=3) were obtained. The printed PEDOT/PSS/GO plastic electrode was applied for the determination of carbofuran in vegetable and fruit samples with recoveries between 94.4 and 101.8 %. 相似文献
The current study reports electrocatalytic oxidation of acetaminophen at screen‐printed electrode (SPE) modified with electrogenerated poly(3,4‐ethylenedioxythiophene) (PEDOT) film. Cyclic voltammetric studies show that the SPE/PEDOT electrode lowers overpotentials and improves electrochemical behavior of acetaminophen (ACAP) in aqueous buffer solutions, compared to the bare SPE. Excellent analytical features are achieved, including high sensitivity, low detection limit and satisfactory dynamic range, by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and flow‐injection amperometry (FIA) under optimized conditions. The proposed methods obtain satisfactory results in detection of acetaminophen in two commercial tablets. 相似文献
We report that poly(3,4‐ethylenedioxythiophene) derived from poly(ionic liquid) (PEDOT:PIL) constitutes a unique polymeric hole‐injecting material capable of improving device lifetime in organic light‐emitting diodes (OLEDs). Imidazolium‐based poly(ionic liquid)s were engineered to impart non‐acidic and non‐aqueous properties to PEDOT without compromising any other properties of PEDOT. A fluorescent OLED was fabricated using PEDOT:PIL as a hole‐injection layer and subjected to a performance evaluation test. In comparison with a control device using a conventional PEDOT‐based material, the device with PEDOT:PIL was found to achieve a significant improvement in terms of device lifetime. This improvement was attributed to a lower indium content in the PEDOT:PIL layer, which can be also interpreted as the effective protection characteristics of PEDOT:PIL for indium extraction from the electrodes.
The synthesis and characterization of poly(3,4‐ethylenedioxythiophene) (PEDOT) using water‐assisted vapor phase polymerization (VPP) and oxidative chemical vapor deposition (oCVD) are reported. For the VPP PEDOT, the oxidant, FeCl3, is sublimated onto the substrate from a heated crucible in the reactor chamber and subsequently exposed to 3,4‐ethylenedioxythiophene (EDOT) monomer and water vapor in the same reactor. The oCVD PEDOT was produced by introducing the oxidant, EDOT monomer, and water vapor simultaneously to the reactor. The enhancement of doping and crystallinity is observed in the water‐assisted oCVD thin films. The high doping level observed at UV–vis–NIR spectra for the oCVD PEDOT, suggests that water acts as a solubilizing agent for oxidant and its byproducts. Although the VPP produced PEDOT thin films are fully amorphous, their conductivities are comparable with that of the oCVD produced ones.
Copper–cobalt bimetal nanoparticles (Cu?Co) have been electrochemically prepared on glassy carbon electrodes (GCEs), which were electrodeposited with conducting polymer nanocomposites of poly(3,4‐ethylenedioxythiophene) (PEDOT) doped with carbon nanotubes (CNTs). Owing to their good conductivity, high mechanical strength, and large surface area, the PEDOT/CNTs composites offered excellent substrates for the electrochemical deposition of Cu?Co nanoparticles. As a result of their nanostructure and the synergic effect between Cu and Co, the Cu?Co/PEDOT/CNTs composites exhibited significantly enhanced catalytic activity towards the electrochemical oxidation of nitrite. Under optimized conditions, the nanocomposite‐modified electrodes had a fast response time within 2 s and a linear range from 0.5 to 430 μm for the detection of nitrite, with a detection limit of 60 nm . Moreover, the Cu?Co/PEDOT/CNTs composites were highly stable, and the prepared nitrite sensors could retain more than 96 % of their initial response after 30 days. 相似文献
Composites of unmodified or oxidized carbon nano‐onions (CNOs/ox‐CNOs) with poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are prepared with different compositions. By varying the ratio of PEDOT:PSS relative to CNOs, CNO/PEDOT:PSS composites with various PEDOT:PSS loadings are obtained and the corresponding film properties are studied as a function of the polymer. X‐ray photoelectron spectroscopy characterization is performed for pristine and ox‐CNO samples. The composites are characterized by scanning and transmission electron microscopy and differential scanning calorimetry studies. The electrochemical properties of the nanocomposites are determined and compared. Doping the composites with carbon nanostructures significantly increases their mechanical and electrochemical stabilities. A comparison of the results shows that CNOs dispersed in the polymer matrices increase the capacitance of the CNO/PEDOT:PSS and ox‐CNO/PEDOT:PSS composites. 相似文献
Organosulfur compounds with multiple thiol groups are promising for high gravimetric energy density electrochemical energy storage. We have synthesized a poly(2,5‐dimercapto‐1,3,4‐thiadiazole) (PDMcT)/poly(3,4‐ethylenedioxythiophene) (PEDOT) composite cathode for lithium‐ion batteries with a new method and investigated its electrochemical behavior by charge/discharge cycles and cyclic voltammetry (CV) in an ether‐based electrolyte. Based on a comparison of the electrochemical performance with a carbonate‐based electrolyte, we found a much higher discharge capacity, but also a very attractive cycling performance of PDMcT by using a tetra(ethylene glycol) dimethyl ether (TEGDME)‐based electrolyte. The first discharge capacity of the as‐synthesized PDMcT/PEDOT composite approached 210 mAh g?1 in the TEGDME‐based electrolyte. CV results clearly show that the redox reactions of PDMcT are highly reversible in this TEGDME‐based electrolyte. The reversible capacity remained around 120 mAh g?1 after 20 charge/discharge cycles. With improved cycling performance and very low cost, PDMcT could become a very promising cathode material when combined with a TEGDME‐based electrolyte. The poor capacity in the carbonate‐based electrolyte is a consequence of the irreversible reaction of the DMcT monomer and dimer with the solvent, emphasizing the importance of electrolyte chemistry when studying molecular‐based battery materials. 相似文献
Poly(3,4‐ethylenedioxythiophene) (PEDOT) films are deposited, using an electroless method, onto flexible plastic poly(ethylene terephthalate) (PET) substrates of approximately 20×6 cm2. The sheet resistance of a PEDOT–PET film is approximately 600 Ω per square, and the nanoscale conductivity is 0.103 S cm?1. A plastic electrochromic PEDOT–Prussian blue device is constructed. The device undergoes a color change of pale blue to deep violet–blue reversibly over 1000 cycles, thus demonstrating its use as a light‐modulating smart window. The PEDOT–PET film is also used in a quantum dot solar cell, and the resulting photoelectrochemical performance and work function indicate that it is also promising for photovoltaic cells. The high homogeneity of the PEDOT deposit on PET, the optimal balance between conductivity and optical transparency, and the demonstration of its use in an electro‐optical device and a solar cell, offer the opportunity to use this electrode material in a variety of low‐cost optoelectronic devices. 相似文献