Surfactant-assisted nanocomposite pencil graphite electrode: A green, practical approach for electrochemical monitoring of Riluzole in different matrices

Abstract

The current study presents an eco-friendly, simple, affordable, selective, and sensitive voltammetric method for determining Riluzole (RLZ) using pencil graphite electrode (PGE) modified with cetyltrimethylammonium bromide (CTAB) and multi-walled carbon nanotubes (MWCNTs); both of them were electropolymerized using cyclic voltammetry onto the electrode surface to form poly(CTAB-MWCNTs)/PGE. The poly(CTAB-MWCNTs) modification significantly enhanced the surface area and the anodic peak current compared to bare PGE. Under the optimum experimental conditions, poly(CTAB-MWCNTs)/PGE showed good linear behavior from 5 × 10⁻⁸ to 1 × 10⁻⁴ M using differential pulse voltammetry. The method achieved a detection limit of 1.55 × 10⁻⁸ and a quantification limit of 4.69 × 10⁻⁸ M, reflecting its enhanced sensitivity compared to the reported RLZ voltammetric methods. The method was reliably applied to quantify RLZ in its dosage form as well as in spiked human plasma, achieving good recoveries of 99.12 % ± 0.44 and 103.46 % ± 1.36, respectively. The eco-friendliness and blueness of the method were assessed using MoGAPI, AGREE, and BAGI, and the method showed excellent greenness and practicality, indicating its suitability for routine use in various applications.