Novel preparation and electrochemiluminescence application of luminol functional-Au nanoclusters for ALP determination

Luminol functional Au nanoclusters (lum-AuNCs) were rapidly prepared in luminol–pepsin alkaline solution. Compared with the individual luminol, AuNCs and the mixture of luminol and AuNCs, the composite of lum-AuNCs had special ECL properties, which caused ca. 100-folds enhancement than the ECL intensity of the mixture. The possible mechanism for the preparation was discussed and the ECL properties of lum-AuNCs were given. The ECL intensity of lum-AuNCs could be inhibited effectively by phenol, which was the catalyzed product of phenyl phosphate disodium (PPNa) under the control of the alkaline phosphatase (ALP). Therefore, an anodic ALP-responsive ECL biosensor was constructed. Under the optimized conditions, the decrement of ECL intensity was linearly correlated to the ALP concentration in the range from 0.3 to 12.0 nmol L−1 with a detection limit of 0.1 nmol L−1. The as-proposed ALP biosensor exhibited high specificity and good stability. Finally, it was used to determining the concentration of ALP in human serums successfully.