Journal of the Mexican Chemical Society最新文献

{"title":"Contribution of Dispersion to the Intrinsic Energy Barriers of Neutral Model Diels-Alder Reactions","authors":"H. Jiménez-Vázquez, Luis Almazán, Adriana Benavides","doi":"10.29356/jmcs.v68i1.1867","DOIUrl":"https://doi.org/10.29356/jmcs.v68i1.1867","url":null,"abstract":"The intrinsic reaction coordinates for the cycloadditions between ethene and 1,3-butadiene, and ethene and cyclopentadiene, were determined at the SCS-MP2/aug-cc-pVTZ level of theory. The energy contents of the points determined for both coordinates were decomposed into their deformation and interaction contributions. From this analysis it is concluded that the higher reaction barrier for the butadiene-ethene cycloaddition can be attributed primarily to the conformational change of butadiene required by the reaction (higher deformation energy). There is also a minor contribution of the interaction term, which is more stabilizing for the cyclopentadiene-ethene reaction. An additional decomposition of these terms into their Hartree-Fock and SCS-MP2 correlation components suggests that the higher stabilization of the transition state of the cyclopentadiene-ethene cycloaddition is mostly due to stronger dispersion interactions between reactants, resulting from the larger contact surface between them, and not to stabilizing electronic effects.   Resumen. Se determinaron las coordenadas intrínsecas de reacción para las cicloadiciones entre eteno y 1,3-butadieno, y eteno y ciclopentadieno al nivel de teoría SCS-MP2/aug-cc-pVTZ. La energía de los puntos obtenidos en ambas coordenadas se descompuso en sus contribuciones de deformación e interacción. A partir de este análisis se concluye que la mayor barrera energética para la cicloadición eteno-butadieno puede atribuirse, principalmente, al cambio conformacional del butadieno requerido por la reacción (mayor energía de deformación). También se encuentra que el término de interacción es más estabilizante para la reacción entre ciclopentadieno y eteno, aunque la contribución de este término es menor. La descomposición adicional de las energías de interacción de estas reacciones en sus componentes de Hartree-Fock y de correlación SCS-MP2, sugiere que la mayor estabilización del estado de transición en la reacción entre ciclopentadieno y eteno, se debe principalmente a la interacción de dispersión más fuertemente estabilizante entre estos reactantes, resultado de la mayor superficie de contacto entre ellos y no a efectos electrónicos estabilizantes.","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"64 21","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139125157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis, in vitro Antitrichomonal Activity, and Docking Study of N-[(4-substituted phenyl)-1,3-thiazol-2-yl]-4-substituted Benzenesulfonamides","authors":"Rubén M. Carballo, Héctor A. Peniche-Pavía, R. Quijano-Quiñones, D. Cáceres-Castillo, G. Mirón-López, Manlio Graniel-Sabido, Andrea Reyes-Cuapio, R. Moo-Puc, Lía S. Valencia-Chan, G. Mena-Rejón","doi":"10.29356/jmcs.v68i1.1975","DOIUrl":"https://doi.org/10.29356/jmcs.v68i1.1975","url":null,"abstract":"Infection by Trichomonas vaginalis has a high incidence/prevalence worldwide. It has been associated with a predisposition to cervical neoplasia or prostate cancer and an increased risk of acquisition of human papillomavirus (HPV) and human immunodeficiency virus (HIV). Besides, resistance to the drugs used for trichomoniasis treatment has increased in the last 30 years. Herein, thirteen phenylthiazolylbenzene sulfonamides were synthesized and evaluated for their in vitro activity against Trichomonas vaginalis. Among them, four derivatives showed higher anti-trichomonal activity than metronidazole (IC50 = 0.93 µM), while their cytotoxicity levels were not significant. These compounds were subject to molecular docking studies using Trichomonas vaginalis ferredoxin as target. The results revealed that the orientation of the nitro group of the active derivatives is toward [2Fe-2S], the cluster responsible for high reactive oxygen species generation. Finally, it was evident that the presence of a nitro group in the structure of the synthesized phenylthiazolylbenzene sulfonamides is essential for their trichomonicidal activity.   Resumen. A nivel mundial la infección por Trichomonas vaginalis tiene una alta incidencia/prevalencia y se ha asociado con una predisposición a padecer neoplasia cervical o cáncer de próstata, así como a generar un mayor riesgo de adquirir el virus del papiloma humano (VPH) y el virus de la inmunodeficiencia humana (VIH). Además, en los últimos 30 años, la resistencia a los fármacos utilizados para el tratamiento de la tricomoniasis ha aumentado. En el presente trabajo, trece sulfonamidas de feniltiazolilbenceno fueron sintetizadas y evaluadas in vitro contra Trichomonas vaginalis. Cuatro de ellas exhibieron una actividad anti-tricomonas mayor que el metronidazol (CI50 = 0.93 µM), a la vez que citotoxicidad no significativa. Por tal motivo, estos compuestos fueron sometidos a estudios de acoplamiento molecular utilizando como diana a la ferredoxina de T. vaginalis. Los resultados revelaron que la orientación del grupo nitro de los derivados activos está dirigida hacia el grupo [2Fe-2S], responsable de la generación de especies de oxígeno altamente reactivas. Finalmente, se evidenció que la presencia de al menos un grupo nitro en la estructura de las sulfonamidas de feniltiazolilbenceno sintetizadas es esencial para su actividad tricomonicida.","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"39 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139125638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of Sodium, Potassium, Calcium and Magnesium in Urine, Using Microwave Plasma - Atomic Emission Spectrometry and Multi-Energy Calibration","authors":"Tania Lizeth Espinoza Cruz, K. Wrobel, Eunice Yanez Barrientos, Alma Rosa Corrales Escobosa, M. Garay-Sevilla, Francisco Javier AcevedoAguilar, K. Wrobel","doi":"10.29356/jmcs.v68i1.1906","DOIUrl":"https://doi.org/10.29356/jmcs.v68i1.1906","url":null,"abstract":"Microwave plasma - atomic emission spectrometry with multi-energy calibration (MP-AES-MEC) was used for the determination of four major elements in urine. In the family of atomic emission spectrometry, the distinctive features of MP-AES are: (i) nitrogen-based toroidal-shape plasma; (ii) good plasma tolerance to total solids; (iii) exceptionally low operating cost. On the other hand, due to relatively low plasma temperature, this technique is susceptible to spectral interferences and sample-to-sample fluctuating baseline is typical limitation, if previous acid digestion is not performed. MEC is a non-conventional quantification method, not requiring baseline correction and it has been selected in this work to achieve reliable determination of Na, K, Ca and Mg in simply diluted urine. The principle underlying MEC is the proportionality between signal intensity and analyte concentration, occurring at any emission line for given element. Accordingly, for each sample, only two solutions were prepared likewise in the one-point standard addition and two analytical runs were performed, yet four experimental points were generated for calibration according with the number of emission lines utilized. Based on the results obtained by analyzing urines from different subjects, the sample dilution fold was selected to adjust the analyte concentration below half of the calibration range (150 for K, 200 for Na, 50 for Ca and 25 for Mg), while the addition of standard was done roughly doubling natural concentration in the diluted sample.  The evaluated instrumental limits of detection were: 0.009 ± 0.005 mg L-1 for K, 0.131 ± 0.011 mg L-1 for Na, 0.050 ± 0.014 mg L-1 for Ca and 0.059 ± 0.010 mg L-1 for Mg (five replicates in different days). Each analysis was performed in triplicate yielding percentage relative standard deviation £ 11 %. The percentage recoveries calculated taking the results obtained in acid-digested samples by external calibration as reference values were in the range: 83.3-102 % for K, 88.4-110 % for Na, 82.9-113 % for Ca and 85.8-108 % for Mg. The capability of the proposed MP-AES-MEC procedure for monitoring four elements in different clinical conditions was demonstrated by analyzing ten urines from diabetic patients and ten from non-diabetic control subjects; statistical differences between these two groups was found for Na and K.   Resumen. La espectrometría de emisión atómica con excitación en plasma de microondas y con el método de calibración multi-energéa (MP-AES-MEC) fueron empleados para la determinación de cuatro elementos mayoritarios en orina. Dentro de la familia de técnicas de espectrometría de emisión atómica, las características distintivas de MP-AES son las siguientes: (i) uso de plasma de nitrógeno con geometría toroidal; (ii) buena tolerancia del plasma a sólidos totales; (iii) excepcionalmente bajo costo de operación. Por otra parte, debido a la relativamente baja temperatura del plasma, una típica limitación de esta técni","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"113 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139126071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding Experimental Facts for the Transformation of Perezone into α- and β-pipitzols","authors":"Fatima Montserrat Soto Suárez, Gabriel Eduardo Cuevas González Bravo, Luis Mauricio Murillo Herrera, Eduardo Hernández-Huerta, Mariana Ortiz Reynoso, Karla Ramírez Gualito, Ramiro Felipe Quijano Quiñones","doi":"10.29356/jmcs.v68i1.1926","DOIUrl":"https://doi.org/10.29356/jmcs.v68i1.1926","url":null,"abstract":"Under thermal conditions perezone, a sesquiterpene quinone, forms an equimolar amount of a- and β-pipitzol through an intermolecular cycloaddition reaction. Computational calculations at M06-2x/6-311++G(2d,2p) level of theory of the transition states and the associated reaction paths allow justifying the experimental observations. Only exo adducts are observed experimentally, which is in line with the calculated energy difference of 6.5 kcal/mol between the transition states associated with the endo and exo adducts. Activation free energy was accurately predicted, those the uncatalyzed thermal process of cycloaddition requires 37.0 kcal/mol. The study of the potential energy surface allows to establish the existence of folded conformers of perezone in the potential energy surface.   Resumen. En condiciones térmicas la perezona, una quinona sesquiterpénica, forma, cantidades equimolares de a- y β-pipitzoles a través de una reacción de cicloadición intramolecular. A nivel M06-2x/6-311++G(2d,2p) el cálculo de los estados de transición y de las trayectorias de reacción asociadas permiten justificar los resultados observados. Desde el punto de vista experimental sólo se forman los aductos exo y no los endo pues los estados de transición relacionados muestran una diferencia energética de 6.5 kcal/mol. La energía de activación calculada para el procedo desprovisto de catálisis es de 37.0 kcal/mol. El estudio de la superficie de energía potencial permite establecer la existencia de confórmeros plegados de la perezona.","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"59 24","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139126682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructures of Binary Oxides with an Inverse Opal Structure Used as Photoelectrodes for Water Splitting","authors":"B. Frontana-Uribe, M. H. Ríos-Domínguez","doi":"10.29356/jmcs.v67i4.1998","DOIUrl":"https://doi.org/10.29356/jmcs.v67i4.1998","url":null,"abstract":"Recently, the weather has experienced changes and these have affected our life style. Fossil fuels used by the human have contributed to climate change and today it is impossible to modify. Researchers have studied different kind of fuels that could use daily. Currently, hydrogen, from water splitting, is the best way to substitute the fossil fuels because water is present around the World. In photoelectrochemistry, the electrodes have a great importance. Behaviour of each semiconductor as , , , , , , , etc., give us individual efficiency respect to solar light. Also, the semiconductor chosen, type of crystallinity and superficial area are important points for achieve high in efficiency. This review shows that inverse opal has a greater contact compared to rod, cauliflower, nanotubes, etc. Different ways to deposit the polystyrene allows us gain more contact area and better photoelectrode efficiency. The main routes used to obtain binary oxides deposits, as electrophoretic, spin coating, vertical submersion, etc., help us to control polystyrene arrangement and obtain a uniform template.  These techniques are discussed along this contribution.\u0000 \u0000Resumen. Recientemente, el clima ha experimentado cambios que han afectado a nuestro estilo de vida. Los combustibles fósiles utilizados por el ser humano han contribuido al cambio climático y hoy es imposible modificarlo. Los investigadores estudian diferentes tipos de combustibles que podrían utilizarse diaria y actualmente, el hidrógeno, a partir de la ruptura de la molécula de agua, es la mejor manera de sustituir los combustibles fósiles porque el agua está presente en todo el mundo. En fotoelectroquímica, los electrodos tienen una gran importancia. El comportamiento de cada semiconductor como TiO2, Fe2O3, NiO, CuO, NiS, ZnO, Cu2O, etc., tiene cada uno una eficiencia individual respecto a la luz solar que reciben. Además, del semiconductor elegido, el tipo de cristalinidad y el área superficial de este son puntos determinantes para alcanzar un alto grado de eficiencia. La presente revisión muestra que el ópalo inverso tiene un mayor contacto y eficiencia en comparación con las varillas, la coliflor, los nanotubos, etc. Diferentes formas de depositar el poliestireno como molde nos permiten obtener mayor área de contacto y mejor eficiencia del fotoelectrodo semiconductor. Las principales vías utilizadas para obtener depósitos de óxidos binarios, como electroforesis vertical, etc., nos ayudan a controlar la disposición del poliestireno y obtener una capa uniforme. Estas técnicas se discuten a lo largo de esta contribución.","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"6 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138585473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Special Issue: Tribute to the electrochemical emeritus researchers of SNI","authors":"Bernardo A. Frontana-Uribe, Norberto Casillas Santana, Guadalupe Ramos Sánchez","doi":"10.29356/jmcs.v67i4.2167","DOIUrl":"https://doi.org/10.29356/jmcs.v67i4.2167","url":null,"abstract":"","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"76 15","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135092842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brief Review of the Role of Polymers in Different Lithium-Ion Conducting Electrolytes for LIBs","authors":"Gregorio Guzman Gonzalez","doi":"10.29356/jmcs.v67i4.1959","DOIUrl":"https://doi.org/10.29356/jmcs.v67i4.1959","url":null,"abstract":"Polymers have played a vital role in developing next-generation energy storage devices. In the progress of lithium-ion batteries (LIBs), polymers have been widely used in the preparation of electrolytes and electrode binders, in both cases, due to their unique intrinsic properties, such as high thermal, mechanical, and electrochemical resistance. However, the main limitation of this type of material is its poor ionic conductivity at room temperature, which depends on its structural properties and preparation techniques. In this review, the fundamental properties and ion transport mechanisms characteristic of different types of ion-conducting polymers, such as solvent-free polymer electrolytes (SPE), gel polymer electrolytes (GPE), and composite polymer electrolytes (CPE), are reported. A current overview of lithium-ion-based battery systems, which can be improved using ion-conducting polymers, is also presented.   Resumen. Los polímeros han tomado un papel fundamental en el desarrollo de dispositivos de almacenamiento de energía de última generación.  En el perfeccionamiento de baterías de ion litio LIBs, los polímeros han sido utilizados ampliamente en preparación de electrolitos y aglomerantes para electrodos, en ambos casos debido a sus propiedades intrínsecas especiales como alta resistencia térmica, mecánica y electroquímica. Sin embargo, la principal limitante de este tipo de materiales es su pobre de conductividad iónica a temperatura ambiente, la cual depende de sus propiedades estructurales y técnicas de preparación. En esta revisión son presentadas las propiedades fundamentales y mecanismos de transporte iónico característicos de los diferentes tipos de polímeros conductores de iones, como los electrolitos poliméricos sin disolventes (SPE), electrolitos poliméricos en gel (GPE) y electrolitos poliméricos compuestos (CPE). También se presenta un panorama actual de los sistemas de baterías basadas en iones litio, que pueden ser mejoradas de mediante el uso de polímeros conductores de iones.","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"172 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139286906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Why Measure Particle-by-Particle Electrochemistry? A Tutorial and Perspective","authors":"Mario A Alpuche Aviles, Salvador Gutierrez-Portocarrero","doi":"10.29356/jmcs.v67i4.2014","DOIUrl":"https://doi.org/10.29356/jmcs.v67i4.2014","url":null,"abstract":"Single-particle electrochemistry has become an important area of research with the potential to determine the rules of electrochemical reactivity at the nanoscale. These techniques involve addressing one entity at the time, as opposed to the conventional electrochemical experiment where a large number of molecules interact with an electrode surface. These experiments have been made feasible through the utilization of ultramicroelectrode (UMEs), i.e., electrodes with at least one dimension, e.g., diameter of 30 μm or less. This paper provides a theoretical and practical introduction to single entity electrochemistry (SEE), with emphasis on collision experiments between suspended NPs and UMEs to introduce concepts and techniques that are used in several SEE experimental modes. We discuss the intrinsically small currents, below 1 nA, that result from the electroactive area of single entities in the nanometer scale. Individual nanoparticles can be detected using the difference in electrochemical reactivity between a substrate and a nanoparticle (NP). These experiments show steady-state behavior of single NPs that result in discrete current changes or steps. Likewise, the NP can have transient interactions with the substrate electrode that result in current blips. We review the effect of diffusion, the main mass transport process that limits NP/electrode interactions. Also, we pointed out the implications of aggregation and tunneling in the experiments. Finally, we provid a perspective on the possible applications of single-element electrochemistry of electrocatalyst. Resumen. La electroquímica de partículas individuales se ha convertido en un área importante de investigación con el potencial de facilitar la comprensión de las reglas de reactividad electroquímica en la escala de nanómetros. Estas técnicas implican abordar una entidad a la vez, en contraste con el experimento electroquímico convencional en el que un gran número de moléculas interactúa con la superficie de un electrodo. Estos experimentos se han vuelto posibles gracias al uso de ultramicroelectrodos (UME, por sus siglas en inglés), es decir, electrodos con al menos una dimensión, como, por ejemplo, el diámetro de 30 μm o menos. Este artículo proporciona una introducción teórica y práctica a la electroquímica de entidad única (SEE, por sus siglas en inglés), con énfasis en los experimentos de colisión entre nanopartículas (NPs) suspendidas y UME para introducir conceptos y técnicas utilizadas en varios modos experimentales de SEE. Discutimos las corrientes intrínsecamente pequeñas, por debajo de 1 nA, que resultan de la superficie electroactiva de entidades únicas en la escala de nanómetros. Las nanopartículas individuales pueden detectarse mediante la diferencia en reactividad electroquímica entre el sustrato y las nanopartículas. Estos experimentos muestran el comportamiento en estado estacionario de NPs individuales que resulta en cambios discretos de corriente o escalones. De manera ","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"23 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135976604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impedance Analysis for the Study of Biofilm Formation on Electrodes: An Overview","authors":"María Concepcion Romero Serrano, Marcela Mendez Tovar","doi":"10.29356/jmcs.v67i4.2005","DOIUrl":"https://doi.org/10.29356/jmcs.v67i4.2005","url":null,"abstract":"Abstract. The application of Electrochemical Impedance Spectroscopy (EIS) in biofilms studies has been long reported due to the great variety and diversity of applications that are involved in many fields, for instance, in Bioelectrochemical Systems (BES), drinking water distribution systems, electrochemical sensors, food industry, medical devices; among others. Microbial attachment and biofilm growth have been extensively investigated using EIS due to their non-destructive nature; however, several studies (using a three-electrode system) have described changes in the electrochemical parameters that model biofilm development. Therefore, this overview focused on the EIS data analysis by an electrical equivalent circuit (eec). The most representative studies on attachment, biofilm formation, Extracellular Polymeric Substances (EPS), and charge transfer phenomena were discussed. Consequently, the goals of this overview are: Distinguish between the ways of studying biofilm growth (in-situ/ex-situ). EIS data validation by Kramers Kronig relations. The discussion of the electrical elements of eec. Due to the heterogeneity of the reviewed information, the biofilms are divided into two groups: strong electroactive and another group: weak electroactive and non-electroactive biofilms. The importance of this manuscript is to present the biofilm-electrode interface by the electrical elements of various biofilms studied under different conditions, establish an overview of the working methods followed by different authors, and discuss the results obtained on diverse biofilms. Lastly, this overview might help as a general outlook for planning further research. Resumen. La aplicación de la Espectroscopía de Impedancia Electroquímica (EIS) en estudios de biopelículas, ha sido ampliamente reportada debido a la gran variedad y diversidad de aplicaciones que están involucradas en diversos campos, por ejemplo, en sistemas bioelectroquímicos (BES), sistemas de distribución de agua potable, sensores electroquímicos, industria alimentaria, dispositivos médicos; entre otros. La adherencia microbiana y el crecimiento de biopelículas se han investigado ampliamente mediante EIS debido a su naturaleza no destructiva; sin embargo, diversos estudios han descrito cambios en los parámetros electroquímicos que modelan el desarrollo de las biopelículas. Por lo tanto, esta revisión general se centró en el análisis de datos de EIS mediante un circuito eléctrico equivalente (eec). Se discutieron los estudios más representativos sobre attachment, formación de biopelículas, Sustancias Poliméricas Extracelulares (EPS) y fenómenos de transferencia de carga. Por consiguiente, los objetivos de esta revisión son Distinguir entre las formas de estudiar el crecimiento de biopelículas (in-situ/ex-situ). La validación de los datos de EIS por relaciones de Kramers Kronig. La discusión de los elementos de eec. Debido a que la información revisada sobre biopelículas es muy heterogénea, las biopelí","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"9 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135976590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Copper-Zinc Superoxide Dismutase (CuZn-SOD) Electrochemical Catalytic Amplification Sensing at Pt Ultramicroelectrodes","authors":"Annelis O. Sánchez-Álvarez, J. Andres Melendez, Mariena Silvestry-Ramos, Carlos R. Cabrera","doi":"10.29356/jmcs.v67i4.1963","DOIUrl":"https://doi.org/10.29356/jmcs.v67i4.1963","url":null,"abstract":"Abstract. Copper/zinc superoxide dismutase (CuZnSOD), a 32.5 kDa metalloprotein with a radius of ca. 2.1 nm, catalyses the superoxide to hydrogen peroxide and molecular oxygen. At the femtomolar concentration range, has been sensed through electrochemical catalytic amplification using a Pt ultramicroelectrode. During amperometric (i vs. t) analysis, cathodic and anodic current transitions peaks were seen, in agreement with the metalloprotein catalytic mechanism. The current amplitudes were analyzed and correspond to the CuZnSOD dimensions. Thermal treatment of metalloprotein samples at 80 °C showed larger current spikes suggesting aggregation without losing its catalytic capability. The size was confirmed by transmission electron microscopy. Resumen. Cuprozinc superóxido dismutasa (CuZnSOD), es una metaloproteina de 32.5 kDa con un radio de aproximadamente 2.1 nm. Esta enzima cataliza la reacción de superóxido a peróxido y oxígeno molecular. Por primera vez, esta proteína es detectada a concentraciones femtomolares haciendo uso de la técnica electroquímica conocida como amplificación catalítica y la tecnología de ultra-microelectrodos de Pt. Durante un análisis amperométrico (curvas i vs. t), se observaron picos transitorios de corriente catódica y anódica que concuerdan con el mecanismo catalítico de la enzima. Al analizar la amplitud de la corriente, la misma concuerda con las dimensiones de CuZnSOD. Luego de exponer la proteína a un tratamiento térmico de 80 °C, CuZnSOD mostró picos de corriente transitorias que sugieren aglomeración de la enzima sin perder su capacidad catalítica. El tamaño fue confirmado por microscopía electrónica de transmisión.","PeriodicalId":17377,"journal":{"name":"Journal of the Mexican Chemical Society","volume":"538 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135976603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}