Preparation, characterization, and bioelectrocatalytic properties of hemoglobin incorporated multiwalled carbon nanotubes-poly-l-lysine composite film modified electrodes towards bromate

The present work describes preparation of hemoglobin-incorporated multiwalled carbon nanotubes-poly-L-lysine (MWCNT-PLL)/Hb) composite modified electrode film modified glassy carbon electrode (GCE) and its electrocatalytic behavior towards reduction of bromate (BrO^-+) in 0.1M acetate buffer (pH5.6). The modified electrode has been successfully fabricated by immobilizing hemoglobin on MWCNT dispersed in poly-L-lysine. The surface morphologies of MWCNT, PLL and Hb were characterized using atomic force microscopy (AFM). The voltammetric features suggested that the charge transport through the film was fast and the electrochemical behavior resembles that of surface-confined redox species. Cyclic voltammetry was used to investigate the electrocatalytic behavior of the modified electrode towards bromate and was compared with that of the CNT-modified as well as bare electrode. The analytical determination of bromate has been carried out in stirred solution at an optimized potential with a sensitivity of 7.56μAmM^-1 and the calibration curve was linear between 1.5×0^-5 to 6.0×0^-3M.