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 IC/IL vs. t1/2 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 cm2, and an average D-value of (1.11×10^−3 ± 1.16×10^−4) m2 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 (1.83×10^−5 ± 1.96×10^−6) cm2 s^−1 was obtained. ΔI 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 3Sb/m and 10Sb/m criteria were used, respectively.