Different tyrosinase carbon paste modified electrodes to determine bisphenol A (BPA) concentration in aqueous solutions have been constructed. Variables examined were in the carbon paste composition and in particular: (i) the immobilized enzyme amount; (ii) the carbon type (powder, single or multi-walled nanotubes); (iii) the nature of the pasting oil (mineral oil, hexadecane and dodecane). For each biosensor type the amperometric response was evaluated with reference to the linear range and sensitivity. Constant reference has been made to the amperometric signals obtained, under the same experimental conditions, towards the catechol, a specific phenolic substrate for tyrosinase. The most efficient biosensors were those constructed by using the following composition for the carbon paste: 10% of tyrosinase, 45% of single wall carbon nanotubes (SWCN) and 45% of mineral oil. This biosensor formulation displayed the following electrochemical characteristics: a sensitivity equal to 138 microA/mM, LOD of 0.02 microM (based on three times the S/N ratio), linear range of 0.1-12 microM and response time of 6 min. This experimental work represents a first attempt at construction of a new carbon nanotube-tyrosinase based biosensor able to determine the concentration of BPA, one of the most ubiquitous and hazardous endocrine disruptors which can pollute the drinking and surface water, as well as many products of the food chain.
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http://dx.doi.org/10.1016/j.bios.2007.03.010 | DOI Listing |
Talanta
January 2025
Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovića 3, 21000, Novi Sad, Serbia.
The sustainable material, biochar (BC) from a hardwood source, was synthesized via pyrolysis process at 400 °C (BC400) and 700 °C (BC700) and used as a modifier during the electrochemical sensor design. The prepared BCs were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, and elemental analysis (CHNS). The development of rapid analytical techniques for detecting pesticides employing a low-cost carbon paste electrode (CPE) modified with BC is a novel strategy to provide a sensitive response to water pollution.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Faculty of Electrical, Electronic, Computer and Control Engineering, Lodz University of Technology, 18. Stefanowskiego Str., 90-924 Lodz, Poland.
Toxic materials are a threat in workplaces and the environment, as well as households. In them, gaseous substances are included, especially ones without any colour or fragrance, due to their non-detectability with the human senses. In this article, an attempt was made to find a solution for its detection in various conditions with the use of intelligent textiles.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Instituto Universitario de Investigación de Ciencia y Tecnología del Hormigón (ICITECH), Universitat Politècnica de València, 46022 Valencia, Spain.
LC3 (limestone calcined clay cement) is poised to become the construction industry's future as a so-called low-carbon-footprint cement. Research into this subject has determined the minimum kaolinite content in calcined clays to guarantee good mechanical performance. This study examines the use of clay from the Valencian Community (Spain), which has a lower kaolinite content than the recommended amount (around 30%) for use in LC3 and how its performance can be enhanced by replacing part of that clay with metakaolin.
View Article and Find Full Text PDFBiomedicines
January 2025
I-MVET Research in Veterinary Medicine, Faculty of Veterinary Medicine, Lusófona University-Lisbon University Centre, 1749-024 Lisbon, Portugal.
Promoting rapid healing is a concern in skin wound treatment, as the increased pain and the loss of functional ability when wounds become chronic create a complex problem to manage. This scoping review aimed to explore the literature and synthesize existing knowledge on the therapeutic use of CO in treating cutaneous wounds. The literature was selected using previously defined inclusion and exclusion criteria, and 22 articles were selected for data extraction.
View Article and Find Full Text PDFLangmuir
January 2025
Institute of Concrete Structures and Building Materials, Gotthard-Franz-Str. 3, Karlsruhe 76131, Germany.
This paper investigates the impact of varying humidity conditions on the carbonation depth in hardened cement paste using a 3-dimensional microscale kinetic Monte Carlo (kMC) approach. The kMC algorithm effectively simulates the carbonation process by capturing the interplay between CO diffusion and relative humidity at the microscale, providing insights into macro trends that align with historical models. The study reveals that the maximum carbonation depth is achieved at relative humidity levels between 55 and 65%, where the balance between water and CO diffusion is optimized.
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