scholarly journals Electrochemical Biosensors Employing Natural and Artificial Heme Peroxidases on Semiconductors

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3692 ◽  
Author(s):  
Bettina Neumann ◽  
Ulla Wollenberger

Heme peroxidases are widely used as biological recognition elements in electrochemical biosensors for hydrogen peroxide and phenolic compounds. Various nature-derived and fully synthetic heme peroxidase mimics have been designed and their potential for replacing the natural enzymes in biosensors has been investigated. The use of semiconducting materials as transducers can thereby offer new opportunities with respect to catalyst immobilization, reaction stimulation, or read-out. This review focuses on approaches for the construction of electrochemical biosensors employing natural heme peroxidases as well as various mimics immobilized on semiconducting electrode surfaces. It will outline important advances made so far as well as the novel applications resulting thereof.

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3281 ◽  
Author(s):  
Melisa del Barrio ◽  
Gabriel Luna-López ◽  
Marcos Pita

Research on biosensors is growing in relevance, taking benefit from groundbreaking knowledge that allows for new biosensing strategies. Electrochemical biosensors can benefit from research on semiconducting materials for energy applications. This research seeks the optimization of the semiconductor-electrode interfaces including light-harvesting materials, among other improvements. Once that knowledge is acquired, it can be implemented with biological recognition elements, which are able to transfer a chemical signal to the photoelectrochemical system, yielding photo-biosensors. This has been a matter of research as it allows both a superior suppression of background electrochemical signals and the switching ON and OFF upon illumination. Effective electrode-semiconductor interfaces and their coupling with biorecognition units are reviewed in this work.


Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 246
Author(s):  
Patrick Severin Sfragano ◽  
Giulia Moro ◽  
Federico Polo ◽  
Ilaria Palchetti

Peptides represent a promising class of biorecognition elements that can be coupled to electrochemical transducers. The benefits lie mainly in their stability and selectivity toward a target analyte. Furthermore, they can be synthesized rather easily and modified with specific functional groups, thus making them suitable for the development of novel architectures for biosensing platforms, as well as alternative labelling tools. Peptides have also been proposed as antibiofouling agents. Indeed, biofouling caused by the accumulation of biomolecules on electrode surfaces is one of the major issues and challenges to be addressed in the practical application of electrochemical biosensors. In this review, we summarise trends from the last three years in the design and development of electrochemical biosensors using synthetic peptides. The different roles of peptides in the design of electrochemical biosensors are described. The main procedures of selection and synthesis are discussed. Selected applications in clinical diagnostics are also described.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leila Gholami ◽  
Vajihe Taghdiri Nooshabadi ◽  
Shiva Shahabi ◽  
Marzieh Jazayeri ◽  
Rana Tarzemany ◽  
...  

AbstractOral mesenchymal stem cells (MSCs) and their secretomes are considered important factors in the field of medical tissue engineering and cell free biotherapy due to their ease of access, differentiation potential, and successful therapeutic outcomes. Extracellular vesicles (EVs) and the conditioned medium (CM) from MSCs are gaining more attraction as an alternative to cell-based therapies due to the less ethical issues involved, and their easier acquisition, preservation, long term storage, sterilization, and packaging. Bone and periodontal regenerative ability of EVs and CM have been the focus of some recent studies. In this review, we looked through currently available literature regarding MSCs’ EVs or conditioned medium and their general characteristics, function, and regenerative potentials. We will also review the novel applications in regenerating bone and periodontal defects.


2021 ◽  
Vol 4 (1) ◽  
pp. 231-247
Author(s):  
Praopim Limsakul ◽  
Krit Charupanit ◽  
Chochanon Moonla ◽  
Itthipon Jeerapan

2021 ◽  
Vol 5 (7) ◽  
pp. 181
Author(s):  
Dibyani Sahu ◽  
Harekrushna Sutar ◽  
Pragyan Senapati ◽  
Rabiranjan Murmu ◽  
Debashis Roy

Graphene has accomplished huge notoriety and interest from the universe of science considering its exceptional mechanical physical and thermal properties. Graphene is an allotrope of carbon having one atom thick size and planar sheets thickly stuffed in a lattice structure resembling a honeycomb structure. Numerous methods to prepare graphene have been created throughout a limited span of time. Due to its fascinating properties, it has found some extensive applications to a wide variety of fields. So, we believe there is a necessity to produce a document of the outstanding methods and some of the novel applications of graphene. This article centres around the strategies to orchestrate graphene and its applications in an attempt to sum up the advancements that has taken place in the research of graphene.


Author(s):  
С.М. Кравцов ◽  
Т.Л. Черноситова

Постановка задачи. Исследование билингвальных художественных произведений, созданных писателями-транслингвами, использующими несколько языков в своей творческой деятельности, является одной из наиболее актуальных проблем теории языка, в частности таких ее областей, как социолингвистика, стилистика, язык и социум, язык и культура. Подобные произведения, переведённые автором с одного языка на другой и адресованные представителям разных этнических сообществ, носят лингвосоциокультурный характер, который достигается писателем посредством создания интертекста, содержащего внутритекстовые вкрапления, основанные на аллегориях, реминисценциях, аллюзиях, цитациях и аппликациях. При этом аппликации принадлежит весьма важная роль в решении задачи формирования лингвокультурного диалога в билингвальном романе. Результаты исследования. Во франкоязычной версии романа Нэнси Хьюстон «Cantique des plaines», созданной в результате осуществленного ею самоперевода англоязычного романа «Plainsong», выявлено много текстовых аппликаций в виде фрагментов песен, с помощью которых автор формирует лингвокультурный диалог, а также создает не только смысловой, но и музыкальный фон произведения. Установлено, что с целью формирования лингвокультурного диалога в билингвальном романе аппликации в виде отрывков песен могут не совпадать в англоязычной и франкоязычной версиях. Данный эффект достигается во франкоязычной версии благодаря использованию цитат с расширением их посредством сочетаний слов; использованию лексем с более конкретным, точным значением, чем у их английских аналогов; использованию паронимов их английских аналогов; использованию дословного перевода песен с английского языка на французский; использованию включения в перевод на французский язык строфы из англоязычной песни с сохранением при переводе рифмы без искажения исходного смысла самой песни. Выводы. Результаты исследования позволяют сделать вывод о том, что аппликация песенных фрагментов в романе Нэнси Хьюстон «Cantique des plaines» / «Plainsong» является довольно продуктивным стилистическим приемом и имеет несколько видов реализации в зависимости от потребности автора в создании определенного смыслового, эмоционального и музыкального фона произведения. Благодаря широкому использованию и адекватному выбору писателем-транслингвом того или иного вида аппликации она служит эффективным способом формирования лингвокультурного диалога в билингвальном романе Нэнси Хьюстон «Cantique des plaines» / «Plainsong. Problem statement. The study of bilingual novels created by translingual writers who use several languages in their creative activities is one of the most urgent problems of language theory, specifically in such areas as sociolinguistics, stylistics, language and society, language and culture. Such works, translated by the author from one language to another and addressed to representatives of different ethnic communities, are of a linguistic and socio-cultural nature, which is achieved by the writer through the creation of an intertext containing intra-textual inclusions based on allegories, reminiscences, allusions, citations and applications. At the same time, the application plays a very important role in problem solving of forming a linguistic and cultural dialogue in a bilingual novel. The results of the study. In the French-language version of Nancy Huston's novel «Cantique des plaines», created as a result of self-translation of the English-language version of her novel «Plainsong», many text applications in the form of fragments of songs are revealed, by means of which the author forms a linguistic and cultural dialogue, and creates not only a semantic, but also a musical background of the novel. It is established that in order to form a linguistic and cultural dialogue in a bilingual novel, applications in the form of song fragments may not coincide in the English and French versions. This effect is achieved in the French-language version through the use of citations with their extension by word combinations; the use of lexemes with a more specific, accurate meaning than their English counterparts; the use of paronyms of their English counterparts; the use of a literal translation of songs from English into French; the use of including a stanza from an English-language song in the translation into French, while preserving the rhyme without distorting the original meaning of the song itself. Conclusion. The results of the analysis lead to the conclusion that the application of song fragments in Nancy Huston's novel «Cantique des plaines» / «Plainsong» is a rather productive stylistic technique and has several types of implementation, depending on the author's need to create a certain semantic, emotional and musical background of the work. Due to the wide use and adequate choice of a particular type of application by a translingual writer, it serves as an effective way of forming a linguistic and cultural dialogue in Nancy Huston's bilingual novel «Cantique des plaines» / «Plainsong». The results of the study indicate that it is relevant not only for the theory of language, but also for Romance and Germanic linguistics.


2010 ◽  
Vol 93 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Petra M Krämer ◽  
Cristina M Weber ◽  
Stephan Forster ◽  
Peter Rauch ◽  
Elisabeth Kremmer

Abstract New rat monoclonal antibodies (mAbs) for DDT [1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane], namely DDT 7C12, DDT 1C1, and DDT 1B2, were developed, characterized, and applied in ELISA both in coating antigen and in enzyme-tracer format. The latter used horseradish peroxidase (HRP) or glucose oxidase as enzymes. The lowest concentration of p,p-DDT was determined with mAb DDT 7C12 and DDT-hapten HRP, with a test midpoint (IC50) of 0.5 ± 0.2 µg/L (n = 10) in 40 mM PBS (phosphate-buffered saline). The mouse anti-rat immunoglobulin lambda-light chain mAb LA1B12 was used as capture mAb. The best IC50 for o,p´-DDT in 40 mM PBS was 1.0 ± 0.3 µg/L (n = 12) and was obtained with mAb DDT 1C1 and DDT-hapten HRP, whereas mAb DDT 1B2 was very selective for p,p-DDT with an IC50 of 4.2 ± 1.6 µg/L (in 40 mM PBS, n = 9). An optical immunosensor was optimized and applied for the analysis of DDT (or DDT equivalents). This immunosensor consists of a bench-top optical readout device and disposable sensor chips, which include the fluidic system. Evanescent field excitation and emission of the fluorophore Oyster<sup/>-645 was used. An IC50 for p,p´-DDT [in 5 (v/v) isopropanol in 40 mM PBS] of 4 µg/L was obtained using DDT 7C12-Oyster-645. ELISA and immunosensor were used for the analysis of p,p-DDT in unspiked and spiked surface water samples. Within the working ranges of these immunotechniques, recoveries ranged from 80 to 120.


1992 ◽  
Vol 292 ◽  
Author(s):  
Kevin P. McGrath ◽  
David L. Kaplan

AbstractA new approach to materials design is presented, utilizing specific recognition and assembly at the molecular level. The approach described exploits the control over polymer chain microstructure afforded by biosynthesis to produce proteinbased materials with precisely defined physical properties. Incorporated into these materials are recognition elements that stringently control the placement and organization of each chain within higher order superstructures. The proteins, designated Recognin A2 through Recognin E2, are recombinant polypeptides designed de novo from both natural consensus sequences and an appreciation of the physical principles governing biological recognition. These materials are designed to examine the forces involved in specific recognition and complexation. through control of charge identity and placement, a pattern for specific interaction can be introduced. A subset of these materials are programmed to spontaneously assemble into complex, multicomponent structures and represent the first step in a rational approach to nanometer-scale structural design.


2015 ◽  
Vol 95 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Brad E. Dicianno ◽  
Bambang Parmanto ◽  
Andrea D. Fairman ◽  
Theresa M. Crytzer ◽  
Daihua X. Yu ◽  
...  

Individuals with chronic conditions and disabilities who are vulnerable to secondary complications often require complex habilitative and rehabilitative services to prevent and treat these complications. This perspective article reviews the evolution of mHealth technologies and presents insights as to how this evolution informed our development of a novel mHealth system, iMHere (interactive mobile health and rehabilitation), and other technologies, including those used by the Veterans Administration. This article will explain the novel applications of mHealth for rehabilitation and specifically physical therapy. Perspectives on the roles of rehabilitation professionals in the delivery of health care using mHealth systems are included. Challenges to mHealth, including regulatory and funding issues, are discussed. This article also describes how mHealth can be used to improve patient satisfaction and delivery of care and to promote health and wellness.


2021 ◽  
Author(s):  
Ruolan Fan ◽  
Jiale Du ◽  
Kwang-Won Park ◽  
Eric Strieter ◽  
Trisha L. Andrew ◽  
...  

To produce next-generation, shelf-stable biosensors for point-of-care diagnostics, a combination of rugged biomolecular recognition elements, efficient encapsulants and innocuous deposition approaches are needed. Furthermore, to ensure that the sensitivity and specificity that is inherent to biological recognition elements is maintained in solid-state biosensing systems, site-specific immobilization chemistries must be invoked such that the function of the biomolecule remains unperturbed. In this work, we present a widely-applicable strategy to develop robust solid-state biosensors using emergent nanobody (Nb) recognition elements coupled with a vapor-deposited polymer encapsulation layer. As compared to conventional immunoglobulin G (IgG) antibodies, Nbs are smaller (12-15 kDa as opposed to ~150 kDa), have higher thermal stability and pH tolerance, boast greater ease of recombinant production, and are capable of binding antigens with high affinity and specificity. Photoinitiated chemical vapor deposition (piCVD) affords thin, protective polymer barrier layers over immobilized Nb arrays that allow for retention of Nb activity and specificity after both storage under ambient conditions and complete desiccation. Most importantly, we also demonstrate that vapor-deposited polymer encapsulation of nanobody arrays enables specific detection of target proteins in complex heterogenous samples, such as unpurified cell lysate, which is otherwise challenging to achieve with bare Nb arrays.


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