Improvement of urease based biosensor characteristics using additional layers of charged polymers

Enzyme inhibition-based biosensors for food safety and environmental monitoring

“…It has been shown that the sensitivity of enzymes toward heavy metal ions is a function of enzyme loading (Soldatkin et al, 2000). These authors have demonstrated that urease immobilization under a negatively charged polymer induces an increase of the inhibition effect of the heavy metal ions due to cation accumulation in the polymeric matrix.…”

Development of urease and glutamic dehydrogenase amperometric assay for heavy metals screening in polluted samples

“…Assays based on the inhibition of urease show a high selectivity for the sensitive and effect-based screening of heavy metals (Jung et al, 1995;Wittekindt et al, 1996;Brack et al, 2000). Most urease inhibition assays are based on the measurement of either pH changes (Shi et al, 1997;Kormos and Lengauer, 2000;Krawczyk et al, 2000) or ammonia production (Gil and Piedade, 1992;Soldatkin et al, 2000). A significant shortcoming of urease inhibition tests based on measurement of ammonia evolution is the limitation to environmental samples with low content of ammonia (Jung et al, 1995).…”

Recent developments in urea biosensors

“…Besides this, they can be obtained in the form of free-standing films for the fabrication of biosensors. Extensive efforts have been made to fabricate urea biosensors using different polymer matrices, such as phosphine oxide polyether [31], polygalacturonate [32], polyurethane-acrylate [33], acrylonitrile [34], hydroxyapatite [35], alginate [36], bovine serum albumin [37], poly(vinyl ferrocenium) [38,39], polyethylenimine [40], synthetic latex polymer, activated polyvinyl alcohol (PVA) [41], polyvinyl chloride (PVC) [42][43][44], and chitosan [45]. These materials provide mechanical strength and long-term stability as supports for the immobilization of the enzymes.…”