A glassy carbon electrode (GCE) was covalently modified by 4-phosphatephenyl (4-PP). Sensing paracetamol (PCT) via linear sweep voltammetry in sulfuric buffer solution of pH 1.02 at 36.8?degrees C, the 4-PP-modified GCE showed high electrochemical sensitivity and long reusability. PCT-loaded poly(vinyl alcohol) (PVA) nanofibers were prepared by electrospinning. Based on the calibration curve of PCT on the 4-PP-modified GCE, the PCT release process from the nanofibers was electrochemically monitored in real time via two routes. The results showed that the covalently modified GCE can be repeatedly used as real-time electrochemical monitoring platform for drug release from drug-loaded nanofibers in the long term.