Microchemical Journal, vol.211, 2025 (SCI-Expanded)
Riociguat (RCG), a crucial therapeutic agent for the treatment of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), addresses increased pulmonary vascular resistance and right ventricular strain by stimulating soluble guanylate cyclase. Precise detection of RCG is essential for therapeutic drug monitoring, pharmacokinetic studies, and quality control. This work presents the development of an advanced electrochemical sensor for the detection of the orphan drug riociguat (RCG), utilizing novel COF-PTA@CuCoFe-LDH microspheres immobilized on a glassy carbon electrode (GCE). COF-PTA@CuCoFe-LDH microspheres were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray Spectroscopy, and Thermogravimetric Analysis (TGA). Under ideal experimental conditions, differential pulse voltammetry (DPV) studies demonstrated that the COF-PTA@CuCoFe-LDH/GCE sensor exhibits strong electrocatalytic activity for the detection of RCG, with a linear range spanning from 0.05 to 16.4 μM. Additionally, the COF-PTA@CuCoFe-LDH/GCE sensor demonstrated a low limit of detection (LOD) of 5.96 nM and a limit of quantification (LOQ) of 19.9 nM. It exhibited excellent repeatability, reproducibility, and selectivity, even in the presence of a range of potential interfering substances. The developed COF-PTA@CuCoFe-LDH/GCE sensor proved effective for the analysis of real samples, containing pharmaceutical tablets, human plasma, and human urine, yielding recoveries ranging from 97.38 % to 102.1 %. These results underscore the sensor's practical applicability and reliability in real-world analytical scenarios.