Development of an amperometric biosensor based on glutathione peroxidase immobilized in a carbodiimide matrix for the analysis of reduced glutathione from serum

An amperometric glutathione biosensor based on chitosan–iron coated gold nanoparticles modified Pt electrode

“…To determine the biosensor storage stability, the amperometric measurements were carried out periodically every fifth day for 4 months. The enzyme electrode lost only 50% of its initial activity after 150 uses during its storage over a period of 4 months, which is better than earlier reports 3 months [44] and 2 months [45][46][47].…”

“…The decrease in the optimum temperature compared to free enzyme (30 • C) might be due to the improvement in the enzyme rigidity upon immobilization through covalent binding. The biosensor showed optimum response within 4 s, which is better than earlier reports [44][45][46]. Fig.…”

“…The current response resulting from the CHIT/Fe@Au modified Pt electrode bound enzyme-catalyzed reaction achieved a maximum value at pH 7.0, which is higher than that for silver nanoparticles/MWCNT/polyaniline film (6.0) [44], clarktype oxygen electrode (6.5) [45] but lower than that of pyrolytic graphite electrode (7.8) [46]. This shift in optimum pH from earlier reported biosensor could be related to the functional groups ( NH 2 ) of the polymer side chain.…”

Electrocatalytic activity of 4-nitrophthalonitrile-modified electrode for the l-glutathione detection

“…According to Table 1, it can be noted that few articles utilize neutral medium for GSH determination. Besides, the oxidation potentials for GSH are relatively high when compared to the present work, and the detection limit and sensitivity of the present work are also better (Table 1) [29,[32][33][34]. Such good sensitivity can be attributed to the efficiency of the electron transfer between 4-nitrosophthalonitrile of the modified mediator to the sulfhydryl group GSH.…”

“…with a correlation coefficient of 0.998 (for n = 10) with better sensitivity and detection limit than those reported in the literature [13,18,[28][29][30][31][32][33][34]. Such good sensitivity of 54 nA L mol −1 can be attributed to the efficiency of the electron transfer between the 4-nitrosophthalonitrile and GSH [20].…”