title: A simple strategy for the immobilization of catalase on multi-walled carbon nanotube/poly (L-lysine) biocomposite for the detection of H2O2 and iodate.
abstract: Herein, we report a novel third-generation H2O2 and IO3- biosensor, which was fabricated by loading catalase (CAT) onto l-lysine/multiwalled carbon nanotube (PLL/f-MWCNT) film modified glassy carbon electrode (GCE). The UV-visible (UV-vis) and Fourier-transform infrared (FTIR) spectra show that the catalase encapsulated in the PLL/f-MWCNT film can effectively retain its bioactivity. The immobilized CAT retained its bioactivity with a high protein loading of 4.072 × 10(-10) mol cm(-2), thus exhibiting a surface-controlled reversible redox reaction, with a fast heterogeneous electron transfer rate of 5.48 s(-1). The immobilized CAT shows a couple of reversible and well-defined cyclic voltammetry peaks with a formal potential (E(0)) of -0.471 V (vs. Ag/AgCl) in a pH 6.5 phosphate buffer solution (PBS). Moreover, the modified film exhibited high electrocatalytic activity for the reduction of hydrogen peroxide (H2O2). It exhibited a wide linear response to H2O2 in the concentration range of 1 × 10(-6) - 3.6 × 10(-3), with higher sensitivity (392 mA cm(-2) M(-1)) and a lower Michaelis-Menten constant (0.224 mM). It provided high-catalytic activity towards H2O2 in a shorter time (5s), with a detection limit of 8 nM. These results indicate great improvement in the electrochemical and electrocatalytic properties of the CAT/PLL/f-MWCNT biosensor, offering a new idea for the design of third-generation electrochemical biosensors.
authors: Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC.
authors: A T
authors: AT
authors: Ezhil Vilian
authors: Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC. Electronic address: smchen78@ms15.hinet.net.
authors: Shen-Ming
authors: SM
authors: Chen
authors: Chemistry Division, Center for Education, Chang Gung University, 259, Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan, ROC. Electronic address: blou@mail.cgu.edu.tw.
authors: Bih-Show
authors: BS
authors: Lou
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D002374:Catalase / Q000737:chemistry / Q000378:metabolism*; D004202:Disinfectants / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000378:metabolism; D007452:Iodates / Q000032:analysis* / Q000378:metabolism; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry; D008958:Models, Molecular; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011107:Polylysine / Q000737:chemistry*
chemical_list: D004202:Disinfectants; D004800:Enzymes, Immobilized; D007452:Iodates; D037742:Nanotubes, Carbon; D011107:Polylysine; D006861:Hydrogen Peroxide; D002374:Catalase
keywords: Biosensor; Catalase; Direct electrochemistry; Multiwall carbon nanotubes