4-Aminobenzoic acid (4-ABA) was covalently grafted on a glassy carbon electrode (GCE) during an electrochemical oxidation process in 0.1 M KCl aqueous solution. The modified electrode was applied to sense paracetamol (PCT) at serials of simulated physiologic conditions, compared to the bare electrode. The results showed that the modified electrode possessed better stability, reusability, and longevity than the bare GCE at room to physiologic temperatures. This indicated that 4-ABA/GCE can be used as the electrochemical sensing platform of PCT at the physiologic condition.