Subnanomolar cyanide detection at polyphenol oxidase/clay biosensors.
A novel, inexpensive, and simple amperometric biosensor based on immobilization of polyphenol oxidase (PPO) into Zn-Al layered double hydroxides, also called anionic clays, is applied for determination of cyanide. The detection of cyanide was performed via its inhibiting action on the PPO electrode. Measurement was carried out with 3,4-dihydroxyphenylacetic acid as enzyme substrate, the enzymatically generated quinoid products being electroreduced at -0.2 V. An extremely sensitive detection limit (0.1 nM) was obtained for cyanide. Enzyme immobilization into an anionic exchanger clay seems to cause an increase in cyanide inhibition effects because of anion accumulation in the clay matrix.
Shan
Dan
D
Laboratoire d'Electrochimie Organique et de Photochimie Rédox, UMR CNRS 5630, Institut de Chimie Moléculaire de Grenoble, FR CNRS 2607, Université Joseph Fourier, Grenoble, France.
Mousty
Christine
C
Cosnier
Serge
S
D015374:Biosensing Techniques / Q000379:methods*; D004156:Catechol Oxidase / Q000032:analysis*; D003486:Cyanides / Q000032:analysis*; D036103:Nanotechnology / Q000379:methods*
D003486:Cyanides; D004156:Catechol Oxidase