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

Abstract

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^â1 s^â1 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 (1.11Ã10^â3 ± 1.16Ã10^â4) m² s^â1 was obtained for the diffusion of loratadine (Lor) towards the electrode surface. When the effective surface area (0.245 cm²) was used in calculations, an average D-value of (1.83Ã10^â5 ± 1.96Ã10^â6) cm² s^â1 was obtained. âI 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.