Electrochemical determination of morphine at ordered mesoporous carbon modified glassy carbon electrode

A sensitive electrochemical detection scheme for morphine has been proposed by utilizing the ordered mesoporous carbon modified glassy carbon electrode (OMC/GCE). The electrochemical behaviour of morphine at the OMC/GCE was investigated by cyclic voltammetry. The modified electrode displayed a decrease in the overpotential (ca. 82 mV) and an obvious increase in the peak current (80 times) compared to the bare glassy carbon electrode (GCE). The results indicated that OMC/GCE remarkably enhanced electrocatalytic activity towards the oxidation of morphine. Linear response was found over the range from 0.1 mu M to 20 mu M with a high sensitivity of 1.74 mu A/mu M and low detection limit of 10 nM (S/N = 3). And the relative standard deviation was 0.86% (n = 5). Moreover, combining with a medium-exchange procedure, the OMC/GCE has also been successfully applied to the selective determination of morphine in urine samples with a low detection limit of 50 nM and satisfied recovery of 96.4%. The good results indicate that the CMC/GCE holds great promise in practical application. (C) 2009 Elsevier B.V. All rights reserved.