Multiwall carbon nanotube based electrochemical sensor for nitrendipine, an antihypertensive drug

Modified electrodes play a significant role in the development of electrochemical sensors. Nanomaterials are widely employed now-a-days for modification because of their electrocatalytic properties and enhanced surface area available for redox reactions. In the present study, multiwall carbon nanotube (MWCNT) modified electrode has been used as an electrochemical sensor for nitrendipine, an important antihypertensive drug. Cyclic voltammograms of nitrendipine exhibit a sharp anodic peak around 440 mV and one broad cathodic peak. Influence of sweep rate and concentration on the peak current and potentials have been investigated. Straight line with good correlation is obtained when the peak current was correlated with the sweep rate. The log peak current and log sweep rate plot yield a slope above 0.5 suggesting adsorption controlled reaction. Nitrendipine show enhanced peak current and decreased peak potential indicating good electrocatalytic activity towards the oxidation, leading to a marked improvement in sensitivity. This drug has been determined by differential pulse adsorptive stripping voltammetry. Systematic variation of preconcentration and stripping parameters result in optimum values. Calibration plot in the linear concentration range 0.01 to 0.3 ng/mL is made and LOD is determined. This electrochemical sensor is successfully used for the determination of the drug in commercial samples.