Abstract
            Background: Nifedipine, known as a calcium channel blocker, is widely used for the treatment  of cardiovascular diseases such as hypertension and angina pectoris. However, its high doses  are toxic and may result in a heartbeat, nausea, vomiting, etc.  
  Methods: In the present research, the bimetallic Fe/Mn-MOF modified carbon-ceramic  electrode (CCE) was used for studying the electrochemical behavior and determination of  nifedipine. The presence of Fe/Mn-MOF on the surface of the CCE as an efficient modifier  caused an increase in the current density of nifedipine oxidation. In this way, optimization  of some effective parameters consisting of buffer type, pH, modifier concentration, etc. was  successfully performed. Moreover, other analytical parameters including reproducibility,  repeatability, stability, and selectivity were investigated.  
  Results: The relative standard deviation (RSD) of peak current was 3.2 % for 10 µmol.L-1  nifedipine. Meantime, the linear range of 1-200 µmol.L-1. Additionally, limit of detection (LOD)  and limit of quantification were obtained 0.24 μmol.L-1 and 0.82 µmol.L-1 respectively. The  results showed that the modified electrode has a good electro-oxidation capability for nifedipine.  Finally, for investigating the accuracy of the fabricated sensing assay, the determination of  nifedipine in drug and human serum samples was performed. The recoveries and the related  RSDs% were obtained 96.4-102% and 2.2-3.6% respectively.  
  Conclusion: This modified electrode exhibited appropriate stability, low cost, simple  preparation, fast response time, high repeatability, and good sensitivity. The obtained results  clearly demonstrate the applicability of the proposed sensing assay in various matrix effects  which does not affect the electrochemical response.