Graphene nanocomposite modified glassy carbon electrode for voltammetric determination of the antipsychotic quetiapine

Graphene nanoplatelets were dispersed in a Nafion matrix and used to modify a glassy carbon electrode for rapid determination of quetiapine (QTP) at the working potential of +990 mV (vs. Ag/AgCl). The material was deposited by drop-casting and characterized by scanning electron microscopy. Owing to the unique properties of graphene and the accumulation capability of the anionic polymer for the cationic target analyte, the modified electrode has a strongly improved limit of detection (22 nM) and works in the 100 nM to 10 μM concentration range. Low-cost quantification of QTP in urine samples without prior extraction was achieved after selective adsorption of QTP at the surface using differential pulse voltammetry. In comparison with HPLC method, the modified electrode allows simpler analysis of QTP in enteric-coated tablets that takes 40 s only.