A new carbon paste electrode modified with MWCNTs and nano-structured molecularly imprinted polymer for ultratrace determination of trimipramine: The crucial effect of electrode components mixing on its performance

A novel carbon nanocomposite paste electrode was prepared and used as a voltammetric sensor for ultratrace determination of trimipramine (TRI) which currently used for the treatment of psychiatric disorders. For this aim, nanoparticles of molecularly imprinted polymer (MIP), synthesized by precipitation polymerization method, and multi-walled carbon nanotubes (MWCNTs) were embedded in a nanocomposite paste electrode. The nanocomposite mixing style demonstrated a significant influence on the final electrode performance. The sensor exhibited linear response range of 1.0 × 10−10–2.5 × 10−8 mol L−1 and very high sensitivity of 2131 μA μ mol L−1. The lower detection limit of the sensor was calculated to be 4.5 × 10–11 mol L−1 (S/N = 3). This sensor was applied successfully for highly selective determination of TRI in pharmaceutical formulations, urine and serum samples without applying any sample pretreatment. •Nano-sized trimipramine-imprinted polymer was synthesized by non-covalent approach.•A carbon paste electrode doubly modified with nano-MIP and MWCNTs was prepared.•The carbon paste components mixing style was shown to be crucially important factor.•The trimipramine selective electrode was used directly in plasma and urine samples.•High sensitivity of 2131 μA μΜ−1 and very low DL of 4.5 × 10–11 M was obtained.