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

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) (2+)(3) has been achieved through the preparation of Ru(phen) (2+)(3)/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)(3)(2+)/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)(3)(2+)/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 x 10(-6) to 1 x 10(-11) M with a detection limit of 5.8 x 10(-12) M. The Ru(phen)(3)(2+)/Nafion modified CNT ceramic electrode shows better detection limit than Ru(phen)(3)(2+)/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)(3)(2+) 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)(3)(2+)/Nafion modified CNT ceramic electrode exhibits outstanding long-term stability and reproducibility. The remarkable extraction capability and outstanding long-term stability of Ru(phen)(3)(2+)/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. (C) 2014 Elsevier B.V. All rights reserved.