electropolymerization Dotaz Zobrazit nápovědu
In this work an application of optical fiber sensors for real-time optical monitoring of electrochemical deposition of ketoprofen during its anodic oxidation is discussed. The sensors were fabricated by reactive magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. ITO tuned in optical properties and thickness allows for achieving a lossy-mode resonance (LMR) phenomenon and it can be simultaneously applied as an electrode in an electrochemical setup. The ITO-LMR electrode allows for optical monitoring of changes occurring at the electrode during electrochemical processing. The studies have shown that the ITO-LMR sensor’s spectral response strongly depends on electrochemical modification of its surface by ketoprofen. The effect can be applied for real-time detection of ketoprofen. The obtained sensitivities reached over 1400 nm/M (nm·mg−1·L) and 16,400 a.u./M (a.u.·mg−1·L) for resonance wavelength and transmission shifts, respectively. The proposed method is a valuable alternative for the analysis of ketoprofen within the concentration range of 0.25⁻250 μg mL−1, and allows for its determination at therapeutic and toxic levels. The proposed novel sensing approach provides a promising strategy for both optical and electrochemical detection of electrochemical modifications of ITO or its surface by various compounds.
- Klíčová slova
- anti-inflammatory drug, drug analysis, electrochemistry, electropolymerization, indium tin oxide (ITO), ketoprofen, lossy-mode resonance (LMR), optical fiber sensor, reactive magnetron sputtering thin film,
- MeSH
- biosenzitivní techniky MeSH
- elektrochemické techniky MeSH
- ketoprofen MeSH
- optická vlákna * MeSH
- sloučeniny cínu MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- indium tin oxide MeSH Prohlížeč
- ketoprofen MeSH
- sloučeniny cínu MeSH
Organic electrochemical transistors (OECTs) have emerged as promising candidates for various fields, including bioelectronics, neuromorphic computing, biosensors, and wearable electronics. OECTs operate in aqueous solutions, exhibit high amplification properties, and offer ion-to-electron signal transduction. The OECT channel consists of a conducting polymer, with PEDOT:PSS receiving the most attention to date. While PEDOT:PSS is highly conductive, and benefits from optimized protocols using secondary dopants and detergents, new p-type and n-type polymers are emerging with desirable material properties. Among these, low-oxidation potential oligomers are highly enabling for bioelectronics applications, however the polymers resulting from their polymerization lag far behind in conductivity compared with the established PEDOT:PSS. In this work we show that by careful design of the OECT geometrical characteristics, we can overcome this limitation and achieve devices that are on-par with transistors employing PEDOT:PSS. We demonstrate that the vertical architecture allows for facile electropolymerization of a family of trimers that are polymerized in very low oxidation potentials, without the need for harsh chemicals or secondary dopants. Vertical and planar OECTs are compared using various characterization methods. We show that vOECTs are superior platforms in general and propose that the vertical architecture can be expanded for the realization of OECTs for various applications.
- Publikační typ
- časopisecké články MeSH
Electropolymerization regime of meso-tetrakis(3-methoxy-4-hydroxyphenyl) porphyrin is optimized to yield films possessing both electrocatalytical and permselective properties towards nitric oxide oxidation. The sensor composed of electrochemically oxidized carbon fiber, covered solely with nickel porphyrin derivative layer electropolymerized using our method, is characterized by high selectivity towards nitrite (1:600), ascorbate (1:8000) and dopamine (>1:80), determined by constant potential amperometry at 830 mV (vs. Ag/AgCl). Selectivity for ascorbate and dopamine as well as detection limit for NO (1.5 nM at S/N=3) is 5-10 times better than parameters usually reported for Nafion coated porphyrinic sensors. Nafion coating can further enhance selectivity properties as well as aids to the stability of the sensors' responses.
- MeSH
- biosenzitivní techniky přístrojové vybavení metody MeSH
- časové faktory MeSH
- dopamin analýza MeSH
- dusitany analýza MeSH
- elektrochemie MeSH
- elektrody MeSH
- fluorokarbonové polymery chemie MeSH
- karbonové vlákno MeSH
- katalýza MeSH
- kyselina askorbová analýza MeSH
- metaloporfyriny chemie MeSH
- nikl chemie MeSH
- oxid dusnatý analýza MeSH
- oxidace-redukce MeSH
- senzitivita a specificita MeSH
- sloučeniny stříbra chemie MeSH
- stříbro chemie MeSH
- uhlík chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- dopamin MeSH
- dusitany MeSH
- fluorokarbonové polymery MeSH
- karbonové vlákno MeSH
- kyselina askorbová MeSH
- metaloporfyriny MeSH
- nikl MeSH
- oxid dusnatý MeSH
- perfluorosulfonic acid MeSH Prohlížeč
- silver chloride MeSH Prohlížeč
- sloučeniny stříbra MeSH
- stříbro MeSH
- uhlík MeSH
Five D-π-A-π-D compounds consisting of the same donor unit (dithieno[3,2-b:2',3'-d]pyrrole, DTP), the same π-linker (2,5-thienylene), and different acceptors of increasing electron-withdrawing ability (1,3,4-thiadiazole (TD), benzo[c][1,2,5]thiadiazole (BTD), 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP), 1,2,4,5-tetrazine (TZ), and benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (NDI)) were synthesized. DTP-TD, DTP-BTD, and DTP-DPP turned out to be interesting luminophores emitting either yellow (DTP-TD) or near-infrared (DTP-BTD and DTP-DPP) radiation in dichloromethane solutions. The emission bands were increasingly bathochromically shifted with increasing solvent polarity. Electrochemically determined electron affinities (|EA|s) were found to be strongly dependent on the nature of the acceptor changing from 2.86 to 3.84 eV for DTP-TD and DTP-NDI, respectively, while the ionization potential (IP) values varied only weakly. Experimental findings were strongly supported by theoretical calculations, which correctly predicted the observed solvent dependence of the emission spectra. Similarly, the calculated IP and EA values were in excellent agreement with the experiment. DTP-TD, DTP-BTD, DTP-TZ, and DTP-NDI could be electropolymerized to yield polymers of very narrow electrochemical band gap and characterized by redox states differing in color coordinates and lightness. Poly(DTP-NDI) and poly(DTP-TD) showed promising electrochromic behavior, not only providing a rich color palette in the visible but also exhibiting near-infrared (NIR) electrochromism.
- Publikační typ
- časopisecké články MeSH
Homovanillate (HVA) and vanilmandelate (VMA) are recognized markers of diseases, including neuroblastoma. However, their detection in urine represents a challenging task due to the complexity of the matrix. Here, a design, synthesis and thorough investigation of polymerizable urea-based receptors interacting with HVA and VMA are reported. The selection of receptor with the best anion recognition properties for electrode coating is based on 1 H-NMR and UV-Vis complexation studies. The sensor is prepared by electropolymerization with progress monitoring by cyclic voltammetry. The deposited layer is characterized by IR and scanning electron microscopy. The obtained sensor shows an electrochemical impedance spectroscopy response to VMA with linear range 9.9×10-6 to 1.2×10-3 M and LOD of 3.4×10-6 M. The sensor selectivity was demonstrated by the determination of VMA level in the presence of 16 μM HVA and in artificial urine with and without phosphates, with standard deviations of 0.11, 0.17 and 0.09, respectively.
- Klíčová slova
- biosensors, electropolymerization, host-guest chemistry, neuroblastoma markers, receptors,
- MeSH
- elektrody MeSH
- lidé MeSH
- neuroblastom * diagnóza moč MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In this study, a sensitive platform was designed for the electrocatalytical oxidation and recognition of ascorbic acid (AA) based on poly(β-cyclodextrin) modified glassy carbon electrode (p(β-CD-GCE). Electropolymerization of β-CD on the surface of GCE was performed on the potential range of -1 to 1.5 V. So, a novel biopolymer was prepared on the surface of GCE towards sensitive recognition of AA in human plasma samples. The developed platform has good sensitivity and accuracy for electrooxidation and detection of AA with lower limit of quantification (LLOQ) of 1 nM and linear range of 1 nM to 100 mM. Moreover, the designed electrochemical sensor was employed for the analysis of AA on human plasma samples with high sensitivity. Based on advantages of p(β-CD) prepared by electropolymerization procedure (green, fast, homogeny, and efficient eletrocatalytical behaviour), this conductive biopolymer showed excellent analytical behaviour towards electrooxidation of AA. It is expected that the prepared polymeric interface is able to use in the analysis of biological species in clinical samples.
- Klíčová slova
- advanced biopolymer, biocompatible materials, electrochemical oxidation, electropolymerization, sensor technology, β-cyclodextrin,
- MeSH
- beta-cyklodextriny MeSH
- biokompatibilní materiály MeSH
- biopolymery MeSH
- elektrochemické techniky * metody MeSH
- kyselina askorbová * MeSH
- lidé MeSH
- propylenglykoly MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- beta-cyklodextriny MeSH
- biokompatibilní materiály MeSH
- biopolymery MeSH
- kyselina askorbová * MeSH
- poly(beta-cyclodextrin) MeSH Prohlížeč
- propylenglykoly MeSH
A carbon fiber brush electrode (CFBE) was newly designed and used as a substrate for both controlled potential electrolysis and atmospheric solids analysis probe (ASAP) mass spectrometry. Electropolymerized and strongly adsorbed products of electrolysis were directly desorbed and ionized from the electrode surface. Electrochemical properties of the electrode investigated by cyclic voltammetry revealed large electroactive surface area (23 ± 3 cm2) at 1.3 cm long array of carbon fibers with diameter 6-9 μm. Some products of electrochemical oxidation of pentabromophenol and 2,4,6-tribromophenol formed a compact layer on the carbon fibers and were analyzed using ASAP. Eleven new oligomeric products were identified including quinones and biphenoquinones. These compounds were not observed previously in electrolyzed solutions by liquid or gas chromatography/mass spectrometry. The thickness around 58 nm and 45 nm of the oxidation products layers deposited on carbon fibers during electrolysis of pentabromophenol and 2,4,6-tribromophenol, respectively, was estimated from atomic force microscopy analysis and confirmed by scanning electron microscopy with energy-dispersive X-ray spectroscopy measurements.
Layered optoelectronic devices are manufactured using multistep procedures that require high precision in the spatial positioning of individual materials. Current technology uses costly and tedious procedures and instrumentation. In this work instead, we propose an approach which exploits the fundamental properties of the substrate to direct the growth of the next layer, here controlled by an electrochemical potential. We have electrochemically synthesized and characterized a series of polymeric materials that are most commonly used in the field. The films produced show gradient monomer ratios embedded in the polymeric film as a function of the distance from the working electrode. Under the optimized conditions, reproducible construction of simple electronic elements, e. g., rectifying diodes, is achieved. We argue that the sequential in situ method leads to gradient composition of polymer chains and the film resulting in the rectification of electric current. We discuss how this system can open new avenues in advanced optoelectronic applications, such as organic light-emitting diodes (OLEDs) or field-effect transistors (OFETs).
- Klíčová slova
- conjugated polymers, diodes, electrochromic materials, electropolymerization, optoelectronic devices,
- Publikační typ
- časopisecké články MeSH
This review is devoted to polypyrrole and its morphology, which governs the electroactivity of the material. The macroscopic properties of the material are strictly relevant to microscopic ordering observed at the local level. During the synthesis, various (nano)morphologies can be produced. The formation of the ordered structure is dictated by the ability of the local forces and effects to induce restraints that help shape the structure. This review covers the aspects of morphology and roughness and their impact on the final properties of the modified electrode activity in selected applications.
- Klíčová slova
- drug delivery, electropolymerization, electrosynthesis, morphology, nano-organization, polypyrrole, sorption,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The aim of this electrochemical study was to ascertain which type of electrochemically deposited carbonyl functionalized polymer represents the most suitable electrode substrate for direct covalent immobilization of biological catalysts (enzymes). For this purpose, a triad of amperometric biosensors differing in the type of conductive polymers (poly-vanillin, poly-trans-cinnamaldehyde, and poly-4-hydroxybenzaldehyde) and in the functioning of selected enzymes (tyrosinase and alkaline phosphatase) has been compared for the biosensing of neurotransmitters (dopamine, epinephrine, norepinephrine, and serotonin) and phenyl phosphates (p-aminophenyl phosphate and hydroquinone diphosphate). The individual layers of the polymers were electrochemically deposited onto commercially available screen-printed carbon electrodes (type C110) using repetitive potential cycling in the linear voltammetric mode. Their characterization was subsequently performed by SEM imaging and attenuated total reflectance FTIR spectroscopy. Molecules of enzymes were covalently bonded to the free carbonyl groups in polymers via the Schiff base formation, in some cases even with the use of special cross-linkers. The as-prepared biosensors have been examined using cyclic voltammetry and amperometric detection. In this way, the role of the carbonyl groups embedded in the polymeric structure was defined with respect to the efficiency of binding enzymes, and consequently, via the final (electro)analytical performance.
- Klíčová slova
- Schiff base formation, amperometric detection, carbonyl functional polymer, catalytic biosensor, electropolymerization, enzyme, phenolic compounds,
- MeSH
- biosenzitivní techniky * metody MeSH
- elektrochemické techniky * metody MeSH
- elektrody MeSH
- polymery chemie MeSH
- reprodukovatelnost výsledků MeSH
- skot MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- polymery MeSH
