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

Abstract

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.

Rapid Determination of the ‘Legal Highs’ 4-MMC and 4-MEC by Spectroelectrochemistry: Simultaneous Cyclic Voltammetry and In Situ Surface-Enhanced Raman Spectroscopy

“…In an effort to quickly respond to a growing need to streamline the delivery of results, several alternative drug testing approaches have been recently suggested [ 8 , 9 ]. For example, electrochemical techniques such as voltammetry [ 10 , 11 , 12 , 13 ] and amperometry have been utilized as novel forensic tools for the detection of drugs [ 14 , 15 ]. These electrochemical techniques adapt well to the required field conditions [ 16 ], offering screening opportunities that can provide on-site decisions to law enforcement before sending evidence to the forensic lab for later analysis and processing [ 17 ].…”

Highly selective tungstate transporter protein TupA from Desulfovibrio alaskensis G20

“…The detection relies on the fact that tungstate affects the activity of the immobilized enzyme. However, this method is highly compromised by the presence of other elements like selenium, iron, calcium or aluminum, that even at low concentration interfere with the heavy metal detection 33 . The remarkable advantage of using TupA_R118K as the bioreceptor component of a sensor is that it’s activity is not affected by the presence of other similar ions like molybdate, sulfate, phosphate or perchlorate, allowing selective detection.…”

Detection of contaminants in water supply: A review on state-of-the-art monitoring technologies and their applications

“…The results showed 0.17 M and 0.46 M for allylthiourea and thioacetamide, respectively. Another enzymatic-based (2-phospho-l-ascorbic acid trisodium salt) biosensor made of screen-printed carbon electrodes with modified gold nanoparticles was used to detect the tungsten ions present in tap water, purified laboratory water and bottled drinking water [382]. More information about the use of membrane-based biosensors for pathogen could be found elsewhere [383][384][385][386].…”

“…Initially, the model-based event detection method involves a signal-to-noise principles using laboratory and sensor test-loop evaluation. Indication of contamination events is derived from the chemical changes in background water quality signals [88,89], [137][138][139][140][141][142][143], [163], [167], [217], [244,245], [429,430] Sensor Placements Approach [372][373][374][375][376][377], [380][381][382][383][384][385][386][387][388], [391], [400][401][402][403][404][405][406][407], [434][435][436][437][438] Event Detection Model-based -High true positive alarm rate -Low false alarm detections -Fast response time -Complicated calibration process -Highly dependable on predictions and estimations -Computationally intensive…”