Greener Approach to Cost‐Effective Electrochemical L‐cysteine Sensing Using Polyaniline‐Modified Carbon Paste Electrodes

Abstract

In this study, we present a facile approach for the green synthesis of polyaniline (PANI) through electrochemical polymerization on a graphitic paste electrode, thus enhancing its use in electrochemical sensing applications. The morphology of the synthesized PANI was observed using scanning electron microscopy (SEM), the crystallinity of the material was studied using XRD, and further functional groups were characterized by FT‐IR and UV spectroscopy. PANI, coated on the surface of a graphitic paste ‐modified electrode (P‐GPME) by controlled electrolysis, demonstrated notable electrocatalytic activity toward L‐cysteine (L‐cyst). The redox behavior of L‐cyst at the P‐GPME surface was investigated using cyclic voltammetry. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 2.4 × 10−6 and 1.21 × 10−5 mol L−1, respectively. These results highlight the potential of P‐GPME for selective and sensitive detection of L‐cyst. Furthermore, the designed electrode was effectively employed for the determination of L‐cyst in urine samples.