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

Abstract

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 2–3 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 O2 or N2, 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.