Amperometric determination of acetic acid with a trienzyme/poly(dimethylsiloxane)-bilayer-based sensor.
A trienzyme sensor for the amperometric determination of acetic acid was prepared by immobilizing acetate kinase (AK), pyruvate kinase (PK), and pyruvate oxidase (PyOx) on a poly(dimethylsiloxane) (PDMS)-coated electrode. AK catalyzes the phospho-transferring reaction between acetic acid and ATP to form ADP; PK, the phospho-transferring reaction between ADP and phosphoenolpyruvate to form pyruvic acid; and PyOx, the oxidation of pyruvic acid with oxygen. The oxygen consumption could be monitored by using the PDMS-coated electrode without interference from the PyOx reaction product, hydrogen peroxide. Thus, the concentration of acetic acid (5 microM-0.5 mM) could be determined from the decrease in the cathodic current at -0.4 V vs Ag/AgCl. This is the first example of a biosensor that can be used for the determination of acetic acid in ethanol-containing food samples. The acetate-sensing electrode could be used for more than one month.
Mizutani
F
F
National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
Sawaguchi
T
T
Sato
Y
Y
Yabuki
S
S
Lijima
S
S
D000084:Acetate Kinase / Q000737:chemistry; D000085:Acetates / Q000032:analysis*; D015374:Biosensing Techniques; D004129:Dimethylpolysiloxanes; D004560:Electricity; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005504:Food Analysis; D008567:Membranes, Artificial; D011770:Pyruvate Kinase / Q000737:chemistry; D011771:Pyruvate Oxidase / Q000737:chemistry; D012828:Silicones
D000085:Acetates; D004129:Dimethylpolysiloxanes; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D012828:Silicones; C013830:baysilon; D011771:Pyruvate Oxidase; D011770:Pyruvate Kinase; D000084:Acetate Kinase