A Chronoamperometric Screen Printed Carbon Biosensor Based on Alkaline Phosphatase Inhibition for W(VI) Determination in Water, Using 2-Phospho-l-Ascorbic Acid Trisodium Salt as a Substrate
| Autor: | Ana Lorena Alvarado-Gámez, María Asunción Alonso-Lomillo, Olga Domínguez-Renedo, María Julia Arcos-Martínez |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Sensors, Vol 15, Iss 2, Pp 2232-2243 (2015) |
| Druh dokumentu: | article |
| ISSN: | 1424-8220 15020223 |
| DOI: | 10.3390/s150202232 |
| Popis: | This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working electrode. Enzymatic activity over 2-phospho-l-ascorbic acid trisodium salt, used as substrate, was affected by tungsten ions, which resulted in a decrease of chronoamperometric current, when a potential of 200 mV was applied on 10 mM of substrate in a Tris HCl buffer pH 8.00 and 0.36 M of KCl. Calibration curves for the electrochemical method validation, give a reproducibility of 5.2% (n = 3), a repeatability of 9.4% (n = 3) and a detection limit of 0.29 ± 0.01 µM. Enriched tap water, purified laboratory water and bottled drinking water, with a certified tungsten reference solution traceable to NIST, gave a recovery of 97.1%, 99.1% and 99.1% respectively (n = 4 in each case) and a dynamic range from 0.6 to 30 µM. This study was performed by means of a Lineweaver–Burk plot, showing a mixed kinetic inhibition. |
| Databáze: | Directory of Open Access Journals |
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