title: Biosensor for chlorogenic acid based on an ionic liquid containing iridium nanoparticles and polyphenol oxidase.
abstract: A biosensor based on the ionic liquid, 1-n-butyl-3-methylimidazolium hexafluorophosphate containing dispersed iridium nanoparticles (Ir-BMI.PF(6)) and polyphenol oxidase was constructed. This enzyme was obtained from the sugar apple (Annona squamosa), immobilized in chitosan ionically crosslinked with oxalate. The biosensor was used for determination of chlorogenic acid by square wave voltammetry. The polyphenol oxidase catalyzes the oxidation of chlorogenic acid to the corresponding o-quinone, which is electrochemically reduced back to this substance at +0.25V vs. Ag/AgCl. Under optimized operational conditions the chlorogenic acid concentration was linear in the range of 3.48x10(-6) to 4.95x10(-5)mol L(-1) with a detection limit of 9.15x10(-7)mol L(-1). The biosensor was applied in the determination of chlorogenic acid in organic and decaffeinated coffee and the results compared with those obtained using the capillary electrophoresis method. The recovery study for chlorogenic acid in these samples gave values of 93.2-105.7%.
authors: Department of Chemistry, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC, Brazil.
authors: Suellen C
authors: SC
authors: Fernandes
authors: Sally K
authors: SK
authors: Moccelini
authors: Carla W
authors: CW
authors: Scheeren
authors: Pedro
authors: P
authors: Migowski
authors: Jairton
authors: J
authors: Dupont
authors: Melina
authors: M
authors: Heller
authors: Gustavo A
authors: GA
authors: Micke
authors: Iolanda C
authors: IC
authors: Vieira
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004156:Catechol Oxidase; D002726:Chlorogenic Acid / Q000032:analysis*; D003069:Coffee / Q000737:chemistry; D004800:Enzymes, Immobilized; D052578:Ionic Liquids; D007495:Iridium; D027845:Malus / Q000201:enzymology; D053758:Nanoparticles / Q000737:chemistry
chemical_list: D003069:Coffee; D004800:Enzymes, Immobilized; D052578:Ionic Liquids; D002726:Chlorogenic Acid; D007495:Iridium; D004156:Catechol Oxidase