title: Novel biosensors for quantitative phytic acid and phytase measurement.
abstract: Phytase (EC 3.1.3.26) and phytic acid (myo-inositol hexaphosphate) play an important environmental role in poultry industry and have a health aspect in food industry. Novel biosensors have been developed for simple, one step quantitative phytic acid and phytase detection. A system based on the sequentially acting enzyme phytase and pyruvate oxidase (POD) was employed for the development of phytase and phytic acid biosensors. Poly(carbamoylsulphonate) (PCS) hydrogel immobilized POD electrode was applied for the detection of phytase. It was based on the indication of phosphate ions produced by the hydrolysis of phytic acid. The phytase biosensor showed a linear response ranging from 0.5 to 6.0 units/ml. A bi-enzyme sensor based on co-immobilization of phytase and POD was developed for the detection of phytic acid on the basis of amperometric detection of the enzymatically-generated hydrogen peroxide at 0.6 V versus Ag/AgCl. It showed a linear response ranging from 0.2 to 2.0 mM with a detection limit of 0.002 mM.
authors.affiliation: Sino-German Nano-Analytical Lab (SiGNAL), Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. chmartin@ust.hk
authors.forename: Wing Cheung
authors.initials: WC
authors.lastname: Mak
authors.forename: Yuk Mui
authors.initials: YM
authors.lastname: Ng
authors.forename: Chiyui
authors.initials: C
authors.lastname: Chan
authors.forename: Wai Kuen
authors.initials: WK
authors.lastname: Kwong
authors.forename: Reinhard
authors.initials: R
authors.lastname: Renneberg
mesh_terms: D010832:6-Phytase / Q000032:analysis* / Q000378:metabolism; D015374:Biosensing Techniques; D006863:Hydrogen-Ion Concentration; D010833:Phytic Acid / Q000032:analysis* / Q000378:metabolism; D011771:Pyruvate Oxidase / Q000378:metabolism; D013696:Temperature; D013997:Time Factors
chemical_list: D010833:Phytic Acid; D011771:Pyruvate Oxidase; D010832:6-Phytase