Catalase immobilization onto magnetic multiwalled carbon nanotubes: optimization of crucial parameters using response surface methodology

چکیده مقاله

In this study catalase (CAT) immobilization onto magnetic multi-walled carbon nanotubes (mMWCNTs)
was undertaken and response surface methodology (RSM) employed to determine the optimum
immobilization conditions. The validity of the predicted values was established by comparing the actual
and estimated values of CAT/mMWCNTs activity, 7.39 and 7.48 mM min1, respectively. The kinetic
parameters of the Michaelis–Menten constant (Km; 8.90 mM) and the maximum velocity of the reaction
(Vmax; 0.040 s1) were calculated for CAT/mMWCNTs in comparison with free CAT in buffer solution
(7.65 mM and 0.047 s1). The saturation magnetization (Ms) parameter for mMWCNTs was obtained at
around 19.8 emu g1, which is considerably higher than that for raw MWCNTs (Ms; 0.63 emu g1) which
shows the successful magnetization of MWCNTs. Furthermore, scanning electron microscopy (SEM) showed
that enzyme molecules successfully immobilized onto mMWCNTs. The obtained results illustrated that
mMWCNTs are potentially able to bind enzyme molecules and reduce the costs of industrial enzyme systems.