Electropolymerized Film of l-Cysteine in the Presence of Deep Eutectic Solvent on NaOH Nanorods Glassy Carbon Electrode for Sensitive Determination of Acyclovir in Biological Fluids

In this work, we combined the wealth of surface modification by polymer thin film in the presence of deep eutectic solvents with rich surface chemistry of carbon electrodes for electrochemical sensing of acyclovir (ACV). Electrochemical sensing of ACV was performed using differential pulse voltammetry. Effect of different experimental parameters such as solution pH, polymer film thickness, type and amount of deep eutectic solvent on sensitivity is studied. The results indicated that the differential pulse response of ACV was linear with its concentration in the range of 0.03 to 0.1~\mu \text{M} with a linear coefficient of 0.9904, and in the range of 0.1 to 3.2~\mu \text{M} with a linear coefficient of 0.9946. The limits of detection and quantification were 0.008~\mu \text{M} and 0.027~\mu \text{M} , respectively. The observation of distinct peaks for ascorbic acid, dopamine, guanine and adenine in the presence of ACV confirmed the excellent selectivity of the fabricated sensor. Finally, the content of ACV in tablets and biological fluids was detected to validate the applicability of proposed modified electrode.