Nanoparticles based solid contact potentiometric sensor for the determination of theophylline in different types of tea extract

Abstract A new carbon paste electrode for the determination of theophylline in different kinds of tea extracts was designed. The proposed sensor was based on the use of tert-Butylcalix[4]arene-tetrakis(N, N-dimethylacetamide) as a sensing ionophore in the presence of MWCNTs-CuO nanohybrid as an efficient transducer. The fabricated sensor displayed a linear response over the concentration range of 1×10-2 – 1×10-7 M of theophylline with LOD of 2.5×10-8 M and Nernstian slope of 58.36 mV/decade. It was characterized by a high level of selectivity, stability, and fast response time (