Electrocatalytic boost up of epinephrine and its simultaneous resolution in the presence of serotonin and folic acid at poly(serine)/multi-walled carbon nanotubes composite modified electrode: A voltammetric study

The present paper describes the new strategy for the development of nanosensor based on dropcasting of multiwalled carbon nanotubes (MWCNTs) followed by electropolymerization of serine (ser) onto the glassy carbon electrode (GCE). The developed nanocomposite sensor was abbreviated as poly(ser)/MWCNTs/GCE and was characterized by using electrochemical impedance spectroscopy (EIS) technique. The EIS results confirmed the fast electron transfer rate at the surface of poly(ser)/MWCNTs/GCE. The proposed sensor exhibited good catalytic activity towards the sensing of epinephrine (EP) individually and simultaneously in the presence of serotonin (5-HT) and folic acid (FA) in 0.1 M phosphate buffer solution (PBS) at pH 7.0. The limit of detection (LOD) and limit of quantification (LOQ) of EP was found to be 6 x 10(-7) M and 2 x 10(-6) M respectively. The fabricated sensor showed excellent precision and accuracy with a relative standard deviation (RSD) of 4.86%. The proposed composite sensor was effectively applied towards the determination of EP in human blood serum and pharmaceutical injection sample. (C) 2015 Elsevier B.V. All rights reserved.