This paper reports on the synthesis of a novel molecularly imprinted composite film using the mathematical modeling. This composite was then used in the electrode modification for the determination of theophylline. The ratio of monomer to template in optimum condition was obtained to be 4. The modification of electrode was performed in the presence of theophylline through the electropolymerization of arginine on the composite of sodium alginate/multiwalled carbon nanotubes (SA-MWCNTs), which had been coated on glassy carbon electrode (GCE). The SA-MWCNTs composite with netlike morphology demonstrated high conductivity and electrocatalytic activity. Cyclic voltammogram of modified electrode (MIP/SA-MWCNTs/GCE) in the presence of theophylline showed a sensitive anodic peak in 1170 mV in buffer solution of phosphate (pH 7.0). The investigation and optimization of the effective factors on the response and electrochemical behavior of target theophylline were accurately done on the surface of the modified electrode. Theophylline response was linearly within the range of 0.01–60.0 μM with detection limit of 3.2 nM. Regarding the added standards, the recoveries were values between 93.4–105%. The function of this electrode was satisfactory in the determination of theophylline in real samples like theophylline tablet, theophylline oral solution and human plasma samples.Graphical abstract
The schematic design of the MIP/SA-MWCNTs/GCE preparation process.