RESUMEN

The persistence and potential toxicity of emergent pollutants pose significant threats to biodiversity and human health, emphasizing the need for sensors capable of detecting these pollutants at extremely low concentrations before treatment. This study focuses on the development of glassy carbon electrodes (GCEs) modified by films of poly-tris(4-(4-(carbazol-9-yl)phenyl)silanol (PTPTCzSiOH), poly-4,4'-Di(carbazol-9-yl)-1,1'-biphenyl (PCBP), and poly-1,3,5-tri(carbazol-9-yl)benzene (PTCB) for the detection of metronidazole (MNZ) in aqueous media. The films were characterized using electrochemical, microscopy, and spectroscopy techniques, including scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Monomers were electropolymerized through cyclic voltammetry and chronoamperometry techniques. Computational methods at the B3LYP/def2-TZVP level were employed to investigate the structural and electrochemical properties of the monomers. The electrochemical detection of MNZ utilized the linear sweep voltammetry technique. Surface characterization through SEM and XPS confirmed the proper electrodeposition of polymer films. Notably, MPN-GCEs exhibited higher detection signals compared to bare GCEs up to 3.6 times in the case of PTPTCzSiOH-GCEs. This theoretical study provides insights into the structural, chemical, and electronic properties of the polymers. The findings suggest that polymer-modified GCEs hold promise as candidates for the development of electrochemical sensors.

RESUMEN

Electrically conducting and semiconducting polymers represent a special and still very attractive class of functional chromophores, especially due to their unique optical and electronic properties and their broad device application potential. They are potentially suitable as materials for several applications of high future relevance, for example flexible photovoltaic modules, components of displays/screens and batteries, electrochromic windows, or photocatalysts. Therefore, their synthesis and structure elucidation are still intensely investigated. This article will demonstrate the very fruitful interplay of current electropolymerization research and its exploitation for science education issues. Experiments involving the synthesis of conducting polymers and their assembly into functional devices can be used to teach basic chemical and physical principles as well as to motivate students for an innovative and interdisciplinary field of chemistry.

Asunto(s)

Electrónica , Polímeros , Humanos , Polímeros/química , Oxidación-Reducción , Estrés Oxidativo

RESUMEN

Intrinsically conducting polymers (ICPs) have been widely utilized in organic electronics, actuators, electrochromic devices, and sensors. Many potential applications demand the formation of thin polymer films, which can be generated by electrochemical polymerization. Electrochemical methods are quite powerful and versatile and can be utilized for investigation of ICPs, both for educational purposes and materials chemistry research. In this study, we show that potentiodynamic and potentiostatic techniques can be utilized for generating and characterizing thin polymer films under the context of educational chemistry research and state-of-the-art polymer research. First, two well-known bifunctional monomers (with only two linking sites)-aniline and bithiophene-and their respective ICPs-polyaniline (PANI) and polybithiophene (PBTh)-were electrochemically generated and characterized. Tests with simple electrochromic devices based on PANI and PBTh were carried out at different doping levels, where changes in the UV-VIS absorption spectra and color were ascribed to changes in the polymer structures. These experiments may attract students' interest in the electrochemical polymerization of ICPs as doping/dedoping processes can be easily understood from observable color changes to the naked eye, as shown for the two polymers. Second, two new carbazole-based multifunctional monomers (with three or more linking sites)-tris(4-(carbazol-9-yl)phenyl)silanol (TPTCzSiOH) and tris(3,5-di(carbazol-9-yl)phenyl)silanol (TPHxCzSiOH)-were synthesized to produce thin films of cross-linked polymer networks by electropolymerization. These thin polymer films were characterized by electrochemical quartz crystal microbalance (EQCM) experiments and nitrogen sorption, and the results showed a microporous nature with high specific surface areas up to 930 m2g-1. PTPHxCzSiOH-modified glassy carbon electrodes showed an enhanced electrochemical response to nitrobenzene as prototypical nitroaromatic compound compared to unmodified glassy carbon electrodes.

RESUMEN

Light emission properties of a fluorene cross-conjugated polymer (PF⁻1) based on the monomer 4,7-bis[2-(9,9-dimethyl)fluorenyl] benzo[1,2,5]thiadiazole are reported. This polymer exhibits solubility at high concentrations, good processability into thin solid films of good quality and a broad emission band with a fluorescence quantum yield of approximately 1. Based on these features, in this paper we implemented the use of PF⁻1 as an active layer in polymer light-emitting diodes (PLEDs) and as a laser gain medium in solution. To get insight on the conducting properties of PF⁻1, two different electron injectors, poly [(9,9-bis(3'-(N,N-dimethylamino) propyl)-2,7-fluorene)-alt-2,7-(9,9⁻dioctylfluorene)] (PFN) and lithium fluoride (LiF), were used in a simple PLED architecture. PLEDs with the PFN film were found to exhibit better performance with a maximum luminous efficiency of 40 cd/A, a turn-on voltage (Von) of approximately 4.5 V and a luminance maximum of 878 cd/m² at 5.5 V, with a current density of 20 A/m². For the lasing properties of PF⁻1, we found a lasing threshold of around 75 µJ and a tunability of 20 nm. These values are comparable with those of rhodamine 6G, a well-known laser dye.