Specific determination of As(V) by an acid phosphatase-polyphenol oxidase biosensor.
An original amperometric biosensor based on the simultaneous entrapment of acid phosphatase (AcP) and polyphenol oxidase (PPO) into anionic clays (layered double hydroxides) was developed for the specific detection of As(V). The functioning principle of the bienzyme electrode consisted of the successive hydrolysis of phenyl phosphate into phenol by AcP, followed by the oxidation of phenol into o-quinone by PPO. The phenyl phosphate concentration was, thus, monitored by potentiostating the biosensor at -0.2 V vs Ag/AgCl to detect amperometrically the generated quinone. The detection of As(V) was based on its inhibitory effect on AcP activity toward the hydrolysis of phenyl phosphate into phenol. The As(V) can be specifically determined in pH 6.0 acetate buffer without any interferences of As(III) or phosphate, the detection limit being 2 nM or 0.15 ppb after an incubation step for 20 min.
Cosnier
Serge
S
Laboratoire d'Electrochimie Organique et de Photochimie Redox, UMR CNRS 5630, ICMG FR CNRS 2607, Universite Joseph Fourier, Grenoble, France. Serge.Cosnier@ujf-grenoble.fr
Mousty
Christine
C
Cui
Xiaoqiang
X
Yang
Xiurong
X
Dong
Shaojun
S
D000135:Acid Phosphatase / Q000378:metabolism*; D001152:Arsenicals / Q000032:analysis* / Q000378:metabolism*; D015374:Biosensing Techniques / Q000379:methods*; D004156:Catechol Oxidase / Q000378:metabolism*; D004566:Electrodes; D007700:Kinetics; D012680:Sensitivity and Specificity
D001152:Arsenicals; D004156:Catechol Oxidase; D000135:Acid Phosphatase