Carbon paste electrode (CPE) was first reported in 1958 by Adams. It has become widely used in electrochemical research due to its often-cited advantages of low ohmic resistance, large potential window, and ease of modification. Ease of modification is one of the most valuable features of CPE. This is due to the well-developed surface of CPE, which has a high adsorptivity for substances. To a large extent, it enhanced
the sensitivity and selectivity of CPE. Beitollahi et al. introduced two methods of the simultaneous determination of UA and FA that applied carbon nanotube modified carbon paste electrode as a working electrode. However, one required the more