An electrochemical interface for direct analysis of amlodipine in tablets and human blood samples

Results of this paper related to fabrication of a simple, selective, stable and sensitive electrochemical sensing platform of amlodipine based on gold nanorods (GNRs)-graphene oxide (GO)-functionalized carbon nanotubes (fCNTs) nanocomposite. GNRs nanocomposite provides at least three important functions for electroanalysis; the roughening of the conductive sensing interface, catalytic features and conductivity properties. Electrochemical studies suggested that the GNRs-GO-fCNTs coated glassy carbon electrode (GCE) provides a synergistic augmentation on the voltammetric behaviour of electrochemical oxidation of amlodipine. After optimization of analytical conditions, the peak currents for amlodipine were found to vary linearly with its concentrations in the wide range of 0.01-1.0 and 1.0-75.0 mu M. The estimated detection limit and sensitivity of the sensor were 3.0 nM and 1.07 mu A mu M-1, respectively. The practical applicability of the proposed method was demonstrated in the assessment of total content of amlodipine in pharmaceutical formulations with sufficient recovery (99.2%). Additionally, a biological relevance of the proposed methodology was demonstrated by analysis of human blood samples with satisfactory recoveries in the range of 98.2-101.8%.