Amperometric biosensor for choline based on layer-by-layer assembled functionalized carbon nanotube and polyaniline multilayer film.

摘要: Conducting polymer film was prepared by electrochemical polymerization of aniline. Multiwalled carbon nanotubes (MWNTs) were treated with a mixture concentrated sulfuric and nitric acid to introduce carboxylic groups the nanotubes. By using layer-by-layer method, homogeneous stable MWNTs polyaniline (PANI) multilayer films alternately assembled on glassy (GC) electrodes. PANI had three main functions: (i) excellent antiinterference ability, (ii) protection ability in favor increasing amount immobilized GC electrodes, (iii) superior transducing ability. The effect electrostatic interaction between positively charged negatively both attributed immobilizing abundant stably, thereby enhancing catalytic activity. PANI-modified electrodes offered significant decrease overvoltage for H2O2 shown be amperometric sensors from +0.2V over wide range concentrations. As an application example, linking choline oxidase (CHOD), amplified biosensor toward prepared. exhibited linear response 1x10(-6) 2x10(-3) M correlation coefficient 0.997, time detection limit (S/N=3) determined 3 s 0.3 microM, respectively. displays rapid expanded as well reproducibility stability.