Vitamin B12 incorporated with multiwalled carbon nanotube composite film for the determination of hydrazine

Electrochemically active composite film containing multiwalled carbon nanotubes (MWCNTs) and vitamin B12 was synthesized on glassy carbon, gold, and indium tin oxide electrodes by the potentiodynamic method. The presence of MWCNTs in the composite film (MWCNT–B12) modified electrode mediates vitamin B12’s redox reaction, whereas vitamin B12’s redox reaction does not occur at bare electrode. The electrochemical impedance spectroscopy studies reveal that MWCNTs present in MWCNT–B12 film enhance electron shuttling between the reactant and electrode surface. The surface morphology of bare electrode, MWCNT film. and MWCNT–B12 composite film was studied using atomic force microscopy, which reveals vitamin B12 incorporated with MWCNTs. The MWCNT–B12 composite film exhibits promising enhanced electrocatalysis toward hydrazine. The electrocatalysis response of hydrazine at MWCNT film and MWCNT–B12 composite film was measured using cyclic voltammetry and amperometric current–time (i–t) curve techniques. The linear concentration range of hydrazine obtained at MWCNT–B12 composite film using the i–t curve technique is 2.0 μM–1.95 mM. Similarly, the sensitivity of MWCNT–B12 composite film for hydrazine determination using the i–t curve technique is 1.32 mA mM−1 cm−2, and the hydrazine’s limit of detection at MWCNT–B12 composite film is 0.7 μM.