Ultrasensitive electrochemiluminescent determination of perphenazine at tris(1,10-phenanthroline)ruthenium(II)/Nafion bulk modified carbon nanotube ceramic electrode via solid-phase microextraction

• Bulk Ru(phen)32+ immobilization method using CNT ceramic electrode is developed.
• It has advantages of outstanding long-term stability and easy surface renewal.
• It has excellent extraction ability toward perphenazine.
• It enables highly sensitive and selective perphenazine detection after extraction.

The applications of carbon nanotube (CNT) as solid-phase extraction matrix and bulk modification material in electrochemiluminescence (ECL) have been demonstrated for the first time. The bulk modification of Ru(phen)32+ has been achieved through the preparation of Ru(phen)32+/Nafion modified CNT ceramic electrode. The bulk modification method has the advantages of easy electrode surface renewal and facile electrode preparation over surface immobilization approaches. Moreover, Ru(phen)32+/Nafion modified CNT ceramic electrode can serve as an excellent solid-phase microextraction matrix because of the presence of CNT in the electrode. The combination of the Ru(phen)32+/Nafion modified CNT ceramic electrode with solid-phase extraction enables ultrasensitive detection of perphenazine. The log–log calibration plot for perphenazine is linear from 1 × 10−6 to 1 × 10−11 M with a detection limit of 5.8 × 10−12 M. The Ru(phen)32+/Nafion modified CNT ceramic electrode shows better detection limit than Ru(phen)32+/Nafion modified graphite ceramic electrode by about two orders of magnitude because of strong adsorption capacity and large adsorbing area of multi-walled CNT as well as low ECL background. It is one of the most sensitive methods for the Ru(phen)32+ ECL determination of coreactants so far. The detection takes less than 3 min, which makes this method promising for on-site detection. This method was also successfully applied for the determination of perphenazine in human urine samples spiked with perphenazine. The Ru(phen)32+/Nafion modified CNT ceramic electrode exhibits outstanding long-term stability and reproducibility. The remarkable extraction capability and outstanding long-term stability of Ru(phen)32+/Nafion modified CNT ceramic electrode as well as the advantages of bulk modification method make the present detection strategy promising for ultrasensitive detection of organic compounds.