An Electrochemical Biosensor for Acrylamide Determination: Merits and Limitations

Abstract

The present work reports the results concerning the development and implementation of the first electrochemical biosensor for acrylamide determination, based on a direct biochemical interaction between the analyte and intact bacterial cells, with intracellular enzymatic activity. The biological recognition element consisted of whole cells of Pseudomonas aeruginosa containing intracellular amidase activity, which catalyses the hydrolysis of acrylamide producing ammonium ion (NH 4 +) and acrylic acid. The transduction process was accomplished by means of an ammonium ion selective electrode. Whole cells were firstly immobilized on single discs of polymeric membranes, such as polyethersulphone, nylon and polycarbonate, which were, then, attached to the surface of the selective electrode. However, it was observed a significant loss of cells each time the biosensor was used, namely at the beginning of the assay, when the membranes were attached to the ammonium electrode, and after the assay, when removed for storage purposes. This evidence determined a premature decrease in the biosensor's stability. Instead of using single membrane discs, a "sandwich" design, with two membrane discs was considered. This way the cells remain contained between the membranes, never contacting the electrode's surface, preventing their premature loss. Consequently, the activity of the biosensor could be maintained for longer periods of time. The analytical performance of the biosensor was evaluated. The best results were obtained when polyethersulphone double membranes were used. A typical response of 120 mV (after 6 min reaction time), a Nernstian slope of 48 mV/decade, a limit of detection of 6.31×10-4 M and a half-life time of 27 days, are examples of some figures of merit observed for this biosensor.

Detection of Acrylamide by Biosensors

“…A typical response of 120 mV (after 6 min reaction time), a Nernstian slope of 48 mV/decade, a limit of detection of 6.31 × 10 −4 M and a half-life time of 27 days, were examples of some figures of merit observed for this biosensor [16]. The biological recognition element consisted of whole cells of P. aeruginosa containing intracellular amidase activity, which catalyzes the hydrolysis of acrylamide-producing ammonium ion (NH 4 + ) and acrylic acid.…”

Acrylamide in food products and the role of electrochemical biosensors in its detection: a comprehensive review

“…This evolution in the immobilization approach represents a signicant contribution to the development of the biosensor for acrylamide detection. 79 Xiulan Sun et al 80 considered another strategy involving the application of a suspension of Pheochromocytoma cells on the surface of a glassy carbon electrode modied with reduced graphene oxide and gold nanoparticles, ensuring efficient cell bioactivity and adherence. The modier nanomaterials used ensure excellent performance by improving electron transfer.…”

“…This evolution in the immobilization approach represents a significant contribution to the development of the biosensor for acrylamide detection. 79…”

Nanomaterials Enabled and Bio/Chemical Analytical Sensors for Acrylamide Detection in Thermally Processed Foods: Advances and Outlook

“…The existence of erroneous selectivity of this sensor toward acetamide and formamide in the sample can result in the occurrence of a false-positive output as well. Considering these limitations, Silva et al further developed the biosensor with the same microbial cells, but this time they were immobilized in between double polyethersulfone membranes without glutaraldehyde (which has a toxic effect on cells) in the form of a sandwich, thus preventing premature loss of cells without directly contacting the electrode surface . The previous biosensor with glutaraldehyde had a LOD of 4.48 × 10 –5 M, while the latter had a LOD of 6.31 × 10 –4 M. Currently, research on developing advanced adhesion technology for whole-cell biosensors are under investigation.…”