A highly sensitive and ecofriendly assay platform for the simultaneous electrochemical determination of rifampicin and isoniazid in human serum and pharmaceutical formulations

Abstract

An ultrasensitive and disposable sensor based on a modified screen-printed carbon electrode (SPCE) was developed for rapid quantification of rifampicin (RIF) and isoniazid (INZ) by differential pulse voltammetry (DPV) in complex media. The surface of the SPCE was simply electrochemically modified with a reduced graphene oxide and nickel hydroxide nanofilm (Ni(OH)₂@rGO/SPCE) and characterized by atomic force microscopy and cyclic voltammetry. Individual and simultaneous detection of RIF and INZ was accomplished using the Ni(OH)₂@rGO/SPCE in the ranges of 1.0 × 10⁻⁹–2.0 × 10⁻⁷ mol L⁻¹ and 2.0 × 10⁻⁷–5.0 × 10⁻⁵ mol L⁻¹ for RIF and 5.0 × 10⁻⁸–1.0 × 10⁻⁶ mol L⁻¹ and 1.0 × 10⁻⁶–1.0 × 10⁻⁴ mol L⁻¹ for INZ with detection limits of 3.0 × 10⁻⁹ mol L⁻¹ and 5.0 × 10⁻⁹ mol L⁻¹, respectively. The developed sensor was successfully applied for the rapid simultaneous determination of analytes in real samples.