title: Amperometric hydrogen peroxide biosensor based on immobilization of hemoglobin on a glassy carbon electrode modified with fe(3)o(4)/chitosan core-shell microspheres.
abstract: Novel magnetic Fe(3)O(4)/chitosan (CS) microspheres were prepared using magnetic Fe(3)O(4) nanoparticles and the natural macromolecule chitosan. Then, using an easy and effective hemoglobin (Hb) immobilization method, an innovative biosensor with a Fe(3)O(4)/CS-Hb-Fe(3)O(4)/CS "sandwich" configuration was constructed. This biosensor had a fast (less than 10 s) response to H(2)O(2) and excellent linear relationships were obtained in the concentration range of 5.0 × 10(-5) to 1.8 × 10(-3) M and 1.8 × 10(-3) to 6.8 × 10(-3) M with a detection limit of 4.0 × 10(-6) M (s/n = 3) under the optimum conditions. The apparent Michaelis-Menten constant K(m) was 0.29 mM and it showed the excellent biological activity of the fixed Hb. Moreover, the biosensor had long-time stability and good reproducibility. The method was used to determine H(2)O(2) concentration in real samples.
authors.affiliation: College of Chemistry and Ecological Engineering, Guangxi University for Nationalities, Nanning 530006, China; E-Mails:  zhangjl1984123@yahoo.cn  (J.-L.Z);  PGtansw@126.com  (S.W.T.);  bczdd_198571@sina.com  (D.-D.Z.);  HZW8188516@126.com  (Z.-W.H.);  miyan9@163.com  (Y.M.);  hzy210@163.com  (Z.-Y.H.).
authors.forename: Xue-Cai
authors.initials: XC
authors.lastname: Tan
authors.forename: Jin-Lei
authors.initials: JL
authors.lastname: Zhang
authors.forename: Sheng-Wei
authors.initials: SW
authors.lastname: Tan
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Zhao
authors.forename: Zen-Wei
authors.initials: ZW
authors.lastname: Huang
authors.forename: Yan
authors.initials: Y
authors.lastname: Mi
authors.forename: Zai-Yin
authors.initials: ZY
authors.lastname: Huang