A dual template imprinted polymer modified electrochemical sensor based on Cu metal organic framework/mesoporous carbon for highly sensitive and selective recognition of rifampicin and isoniazid

A highly sensitive and selective doubly imprinted polymer modified electrochemical sensor based on copper metal organic framework/mesoporous carbon (Cu-MOF/MC) composite was developed for simultaneous determination of Rifampicin (RIF) and Isoniazid (INZ). The molecularly imprinted polymer (MIP) film was formed on the surface of Cu-MOF/MC modified glassy carbon electrode (GCE) by incorporating RIF and INZ as template molecules during electropolymerization of pyrrole, followed by removal of both the template molecules. During this process of sensor fabrication, large numbers of complementary binding sites for template molecules are created on the surface of MIP sensor due to high surface area offered by Cu-MOF/MC composite. Various parameters influencing the performance of MIP sensor such as number of electropolymerization cycles and template: monomer ratio were optimized during the study. Based on the optimized parameters, the electrochemical response of Cu-MOF/MC/MIP/GCE towards determination of RIF and INZ was studied in a wide linear working range of 0.08 μM to 85 μM employing adsorptive stripping differential pulse voltammetry in aqueous as well as real samples. The limit of detection was found to be 0.28 nM and 0.37 nM for RIF and INZ respectively. In addition, the MIP sensor showed good stability, acceptable reproducibility and high selectivity for RIF and INZ over other common interferents. Moreover, the developed sensor was successfully applied for simultaneous determination of RIF and INZ in pharmaceutical formulations, blood serum and urine samples with satisfactory recoveries.