potentiometric screen-printed sensor for determination of oxybutynin hydrochloride

The present work describes the fabrication of disposable screen-printed oxybutynin hydrochloride (oxb) potentiometric sensors. the electrode matrix composition was investigated on the basis of the effect of the nature and concentration of sensing ionophores, anionic sites, plasticizers and nanomaterials. incorporation of single-walled carbon nanotubes (swcnts) as transducer and (2, 3, 6-tri-o-methyl)-β-cyclodextrin as molecular recognition elements in the electrode matrix improved both the sensitivity and selectivity of the sensor towards oxybutynin hydrochloride. the fabricated sensors showed nernstian slope of 57.5 ± 1.0 mv decade−1 in the concentration range from 10–6 to 10–2 mol l−1 oxb with detection limit of 8 × 10–7 mol l−1. moreover, the presence of swcnts in the electrode matrix enhanced the potential reading stability, response time (< 4 s) and increased life time of the sensors (5 months). the developed sensors were successfully applied for determination of oxb in pharmaceutical formulations and biological fluids with agreeable average recoveries compared with the official methods.