Determination of meloxicam in plasma samples using a highly selective and sensitive voltammetric sensor based on carbon paste electrodes modified by molecularly imprinted polymer nanoparticle–multiwall carbon nanotubes

Abstract

In this study, a highly selective voltammetric sensor is introduced for the monitoring of meloxicam by using a new carbon paste electrode (CPE). A meloxicam molecularly imprinted polymer (MIP) and a non-imprinted polymer (NIP), polymerizing on the surface of functionalized multiwall carbon nanotubes (MWCNTs), were synthesized and then used for the preparation of carbon paste electrodes (CPEs) to improve the selectivity and conductivity of the prepared sensor. The sensor was applied for the determination of meloxicam using the cathodic stripping voltammetric method. The MIP@MWCNT–CP electrode showed higher recognition ability in comparison to the NIP@MWCNT–CP. Some parameters affecting the sensor response were optimized and then the calibration curve was plotted. Under optimized conditions, two linear dynamic ranges from 4.33 × 10⁻⁵ to 2.85 × 10⁻³ mg L⁻¹ and 2.85 × 10⁻³ to 7.53 × 10⁻² mg L⁻¹ were obtained. The detection limit and quantitation limit of the sensor were calculated to be 3.22 × 10⁻⁵ and 1.1 × 10⁻⁴ mg L⁻¹, respectively, which indicated the sensitivity of the proposed procedure. The proposed sensor is applied to determine meloxicam in plasma samples and the recovery results were found to be between 98.0 and 102.5% using the voltammetric method with acceptable precision of less than 3.1%.