Multichannel electrogenerated chemiluminescence of lucigenin in neutral and alkaline aqueous solutions on a gold nanoparticle self-assembled gold electrode

The electrogenerated chemiluminescence (ECL) of lucigenin on a gold nanoparticle self-assembled gold electrode in neutral and alkaline solutions was studied under conventional cyclic voltammetry (CV) conditions. The gold nanoparticle self-assembled gold electrode exhibited excellent ECL property for the lucigenin ECL system. In alkaline solution, one sharp peak and a shoulder peak were observed at -0.24 and -0.36 V, respectively, on the curve of ECL intensity versus potential and the intensities of these peaks were enhanced by 23 orders of magnitude compared with those on a bare gold electrode. In neutral solution, two strong ECL peaks (ECL signal/noise = 100-1000) were also observed on a gold nanoparticle self-assembled gold electrode, whereas the two ECL peaks were undetectable on a bare gold electrode. These peaks were found to depend on gold nanoparticles on the surface of the electrode, potential scan direction and scan rate, the presence of O-2 or N-2, the pH, the concentration of lucigenin and electrolyte, and surfactant. The emitter of all ECL peaks was identified as N-methylacridone (NMA). The mechanism for the formation of these ECL peaks has been proposed. The results indicate that strong ECL signals of lucigenin system could be obtained on a gold nanoparticle self-assembled gold electrode both in alkaline and neutral solutions, which is even stronger than that of luminol system on a gold nanoparticle self-assembled gold electrode under the optimization conditions. Moreover, the gold nanoparticle self-assembled gold electrode also exhibits good stability for the lucigenin ECL system, overcoming the problem of electrode fouling on a traditional electrode. (c) 2006 Elsevier B.V. All rights reserved.