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.