Abstract
In this paper, a simple, rapid, sensitive, and accurate method for detecting procaine and catechol was developed based on functionalized multi-walled carbon nanotube (f-MWCNTs) and polyglutamic acid (PGA) interactions. For pharmaceutical quality control and physiology research was developed using a PGA/f-MWCNTs modified electrodes. Cyclic voltammetry (CVs), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) were applied to characterize the assembly process of the modified electrode. CVs of excellent linearity (r > 0.99) between oxidation peak current and concentration was obtained in the range of 9.0 x 10(-7)-8.3 x 10(-5) M for procaine and 8.2 x 10(-5)-2.3 x 10(-4) M for catechol in pH 7.0 PBS. The amperometric results revealed that procaine and catechol, respectively, showed well-defined oxidation current. Due to the high affinity of procaine and catechol for PGA and high stability of the propounded sensing platform, the fabricated biosensor achieved ultrasensitive detection with good sensitivity, acceptable reproducibility and stability. Linear sweep voltammetry (LSV) was well separation of the current peaks for these two compounds in voltammetry enables us to simultaneously determine them. Therefore, the combination of f-MWNT and the special binding group between PGA provides an efficient and promising platform for the fabrication of bioelectrochemical devices.