Electrochemical determination of citalopram using a poly (L-serine) film-modified glassy carbon electrode

Citalopram, is an antidepressant drug of the selective serotonin re-up take inhibitor (SSRI) class, which has been developed by H. Lundbeck A/S (Denmark). This drug is used for the symptomatic relief of depressive illness [1- 3]. For drug development and for treatment purposes, it is important to be able to quantify the drug and its metabolites in biological samples and also in pharmaceutical products. This implies the need for analytical methods with high sample-throughput, low limits of detection, and low maintenance cost.In this work, A polymerized film of L-serine was prepared on the surface of a glassy carbon electrode (poly(L-serine/GCE) by electropolymerization using cyclic voltammetry. The polymer film- modified electrode was successfully used for the determination of citalopram. The surface morphology of the modified electrode was characterized by field emission scanning electron microscopy. Under the optimized conditions, a significant electrochemical improvement was observed toward the electrooxidation of citalopram on the modified electrode surface relative to the unmodified electrode. The oxidation peak current of citalopram was proportional to its concentration over the range from 0.49 to 9.8 µM. The limit of detection was evaluated to be 0.27 µM. The proposed method was sensitive and simple. It was successfully employed to determine citalopram in pharmaceutical and human serum samples.