Modified Laccase-Gold Nanoparticles-Tetrathiafulvalene-SPCEs Based Biosensor to Determine W(VI) in Water
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| Autores: | , |
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| Formato: | artículo original |
| Fecha de Publicación: | 2017 |
| Descripción: | It was developed an amperometric biosensor to determine tungsten in water, based on the inhibition of laccase enzyme, by tungsten ions using pyrocathecol as a substrate. The enzyme was immobilized with a proper mixture containing, bovine serum albumin, and glutaraldehyde, for a cross-linking process over screen-printed carbon electrodes, previously modified with tetrathiafulvalen and gold nanoparticles. Optimized experimental conditions are: pyrocatechol in cell 0.040 mM in a phosphate buffer pH 6.5 and applied potential +350 mV. The repeatability and reproducibility, in terms of relative standard deviation values, of de developed biosensor were 3.3 % (n=3), and 2.2 % (n = 5) respectively, and detection limit was 1.8 × 10-7 mol L-1. Additionally it was determined the kinetics of the systems by means of Michaelis-Menten Km apparent constants, calculated using Lineweaver-Burk plots, with and without tungsten. Kinetic study resembles to be competitive inhibition. A recovery study was performed with spiked blanks with a tungsten certified reference standard, traceable to NIST, giving as a result 102.3 ± 6.7 %; tap water samples analyzed presented a mean concentration of 1.75 µM, and recovery of the tungsten certified reference standard on the tap water samples gave 98.8 ± 3.1 %. |
| País: | Kérwá |
| Institución: | Universidad de Costa Rica |
| Repositorio: | Kérwá |
| OAI Identifier: | oai:kerwa.ucr.ac.cr:10669/80661 |
| Acceso en línea: | https://www.sensorsportal.com/HTML/DIGEST/P_2915.htm https://hdl.handle.net/10669/80661 |
| Palabra clave: | Biosensor Cathecol Gold nanoparticles Laccase Screen printed carbon electrodes Tetrathiafulvalen Tungsten Water |