Electrochemical amperometric sensing of loratadine using NiO modified paste electrode as an amplified sensor

A modified carbon paste electrode with NiO nanoparticles showed an excellent electrocatalytic behavior towards loratadine in the voltammetric and chronoamperometric approaches. Typical plots of I-C/I-L vs. t(1/2) were contracted, and an average rate constant of 185.5 +/- 2.2 M-1 s(-1) was obtained from the slope of the curve. The geometric surface area of the electrode was 0.0314 cm(2), and an average D-value of (1.11x10(-3) +/- 1.16x10(-4)) m(2) s(-1) was obtained for the diffusion of loratadine (Lor) towards the electrode surface. When the effective surface area (0.245 cm(2)) was used in calculations, an average D-value of (1.83x10(-5) +/- 1.96x10(-6)) cm(2) s(-1) was obtained. Delta I response is the peak current difference of the electrode at a fixed time when Lor analyte was added, and it is in proportion to the loratadine concentration in the range of 20-1000 nM. The limit of detection (LOD) and the limit of quantification (LOQ) of the method were 1.4 and 4.7 nM Lor when the 3S(b)/m and 10S(b)/m criteria were used, respectively.