Investigation of electrochemical behaviour and determination of Riociguat with bare GCE and molecularly imprinted polymer-based electrochemical sensor

Abstract

Pulmonary Arterial Hypertension (PAH) causes death due to ventricular overload and heart failure. Calcium channel blockers, anticoagulants, digoxin and diuretics are the standards of care for PAH. Riociguat (RIO) is an oral soluble guanylate cyclase stimulator approved for the treatment of PAH by World Health Organization (WHO) Group 1 patients. In this study, the electrochemical behavior of RIO was investigated using a bare glassy carbon electrode (GCE). In addition, RIO was determined using GCE and a molecularly imprinted polymer (MIP)based electrochemical sensor. The MIP-based electrochemical sensor was prepared by photopolymerization of methacrylic acid in the presence of a basic monomer, crosslinker, target molecule, and photoinitiator. The polymer film was characterised by a scanning electron microscope (SEM) and cyclic voltammetry (CV). Under the optimized conditions, the results obtained with GCE and MIP sensor were compared. The analytical performance of GCE and MIP-based electrochemical sensors was evaluated. The linear ranges of RIO were 1.0 x 10-6 - 1.0 x 10-4 M and 1.0 x 10-13 - 1.0 x 10-12 M, with a limit of detection (LOD) of 1.40 x 10-8 M and 2.12 x 10-14 by bare GCE and MIP-based electrochemical sensor using differential pulse voltammetry (DPV), respectively. The results show that the MIP sensor has higher sensitivity than the bare GCE. Both were applied to commercial human serum samples and pharmaceutical dosage forms. The recovery studies were performed, and the recovery % and RSD% results are within the acceptable range. Therefore, the GCE and MIP sensors have good selectivity, accuracy and precision.