Direct electrochemistry of catalase at multiwalled carbon nanotubes - nafion in presence of needle shaped DDAB for H2O2 sensor Export

@article{citeulike:4179606, abstract = {The direct electrochemistry of catalase (CAT) at didodecyldimethylammonium bromide (DDAB) present on nafion dispersed multiwalled carbon nanotubes (MWCNTs-NF) modified glassy carbon electrode (GCE) has been reported. The presence of DDAB in MWCNTs-NF-CAT film enhances the surface coverage concentration of CAT (Fe III/II ) to 48\%. Similarly, in presence of DDAB, there is a 57\% enhancement in electron transfer rate ( k s ) with 66\% increase in CAT stability. And the same Fe III/II redox couple exhibits linear dependence with the pH variation (−51 mV pH −1 ). The UV-visible absorption spectroscopy study reveals the entrapped CAT in DDAB film retains its native structure at MWCNTs-NF modified electrodes. Similarly, electrochemical impedance spectroscopy results confirm the co-existence of CAT and DDAB in the modified film. Further, scanning electron microscopy results reveal the structural morphological difference between various components in MWCNTs-NF-(DDAB/CAT) film. The cyclic voltammetry (CV) and amperometry (i-t curve) have been used for the measurement of electroanalytical properties of H 2 O 2 by means of various film modified GCEs. The sensitivity values of MWCNTs-NF-(DDAB/CAT) film for H 2 O 2 using CV (35.62 μA mM −1  cm 2 ) are higher than the values which are obtained for MWCNTs-NF-CAT film (2.74 μA mM −1  cm 2 ). Similarly, the sensitivity values using i-t curve are 101.74 μA mM −1  cm 2 for MWCNTs-NF-(DDAB/CAT) and 74.69 μA mM −1  cm 2 for MWCNTs-NF-CAT film. Finally, the diffusion coefficient of H 2 O 2 at MWCNTs-NF-(DDAB/CAT) film (3.4 × 10 −10  cm 2  s −1 ) has been calculated using rotating disc electrode studies.}, author = {Prakash, Periasamy A. and Umasankar, Yogeswaran and Chen, Shen-Ming}, citeulike-article-id = {4179606}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.talanta.2009.02.033}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S0039914009001702}, day = {24}, doi = {10.1016/j.talanta.2009.02.033}, issn = {00399140}, journal = {Talanta}, keywords = {bromide, carbon, catalase, didodecyldimethylammonium, direct, electrocatalysis, electrochemistry, hydrogen, multiwalled, nanotubes, peroxide}, month = {February}, posted-at = {2009-03-15 18:33:42}, priority = {2}, title = {Direct electrochemistry of catalase at multiwalled carbon nanotubes - nafion in presence of needle shaped DDAB for H2O2 sensor}, url = {http://dx.doi.org/10.1016/j.talanta.2009.02.033}, year = {2009} }

TY - JOUR ID - citeulike:4179606 L3 - citeulike-article-id:4179606 N2 - The direct electrochemistry of catalase (CAT) at didodecyldimethylammonium bromide (DDAB) present on nafion dispersed multiwalled carbon nanotubes (MWCNTs-NF) modified glassy carbon electrode (GCE) has been reported. The presence of DDAB in MWCNTs-NF-CAT film enhances the surface coverage concentration of CAT (Fe III/II ) to 48%. Similarly, in presence of DDAB, there is a 57% enhancement in electron transfer rate ( k s ) with 66% increase in CAT stability. And the same Fe III/II redox couple exhibits linear dependence with the pH variation (−51 mV pH −1 ). The UV-visible absorption spectroscopy study reveals the entrapped CAT in DDAB film retains its native structure at MWCNTs-NF modified electrodes. Similarly, electrochemical impedance spectroscopy results confirm the co-existence of CAT and DDAB in the modified film. Further, scanning electron microscopy results reveal the structural morphological difference between various components in MWCNTs-NF-(DDAB/CAT) film. The cyclic voltammetry (CV) and amperometry (i-t curve) have been used for the measurement of electroanalytical properties of H 2 O 2 by means of various film modified GCEs. The sensitivity values of MWCNTs-NF-(DDAB/CAT) film for H 2 O 2 using CV (35.62 μA mM −1  cm 2 ) are higher than the values which are obtained for MWCNTs-NF-CAT film (2.74 μA mM −1  cm 2 ). Similarly, the sensitivity values using i-t curve are 101.74 μA mM −1  cm 2 for MWCNTs-NF-(DDAB/CAT) and 74.69 μA mM −1  cm 2 for MWCNTs-NF-CAT film. Finally, the diffusion coefficient of H 2 O 2 at MWCNTs-NF-(DDAB/CAT) film (3.4 × 10 −10  cm 2  s −1 ) has been calculated using rotating disc electrode studies. JF - Talanta SN - 00399140 TI - Direct electrochemistry of catalase at multiwalled carbon nanotubes - nafion in presence of needle shaped DDAB for H2O2 sensor KW - bromide KW - carbon KW - catalase KW - didodecyldimethylammonium KW - direct KW - electrocatalysis KW - electrochemistry KW - hydrogen KW - multiwalled KW - nanotubes KW - peroxide AU - Prakash, Periasamy AU - Umasankar, Yogeswaran AU - Chen, Shen-Ming PY - 2009/02/24/ UR - http://dx.doi.org/10.1016/j.talanta.2009.02.033 ER -