2‐(4‐Ferrocenyl‐1,2,3‐triazol‐1‐yl)‐1‐(naphthalen‐2‐yl)ethanone (2FTNE) and magnetic core–shell manganese ferrite nanoparticles (CMNP) were fabricated and applied to produce a modified carbon paste electrode (CPE). The electrochemical behaviour of ascorbic acid (AA) was investigated using cyclic voltammetry and measured by square wave voltammetry along with that of uric acid (UA) and folic acid (FA). The 2FTNECMNP‐modified CPE (2FTNECMNPPE) had electrocatalytic activity towards AA oxidation that was greater than that of bare CPE and CMNP‐modified CPE. Based on the results, the linear oxidation peak current was 0.01–60 μM for AA level and the correlation coefficient was 0.9997. According to three times the standard deviation for the blank, the limit of detection was calculated as 0.002 μM. Our results showed an increase in selectivity, stability and reproducibility for 2FTNECMNPPE, which significantly could measure AA, UA and FA levels in AA ampoule, FA tablet and urine samples. It can be concluded that 2FTNECMNPPE has promising capacity in the development of electrochemical sensors.
